MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Insect Biochemistry and Molecular Biology' source. Thu, 09 Feb 2012 13:38:35 +0100 http://www.medworm.com/index.php?rid=5619134&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22245367%26dopt%3DAbstract Authors: Soulages JL, Firdaus SJ, Hartson S, Chen X, Howard AD, Arrese EL Abstract The lipid droplets (LDs) are intracellular organelles mainly dedicated to the storage and provision of fatty acids. To accomplish these functions the LDs interact with other organelles and cytosolic proteins. In order to explore possible correlations between the physiological states of cells and the protein composition of LDs we have determined and compared the proteomic profiles of lipid droplets isolated from the fat bodies of 5th-instar larvae and adult Manduca sexta insects and from ovaries. These LD-rich tissues represent three clearly distinct metabolic states in regard to lipid metabolism: 1) Larval fat body synthesizes fatty acids (FA) and accumulates large amounts as triglyceride (TG); 2) Fa... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5619134 Thu, 05 Jan 2012 05:00:00 +0100 5619134 http://www.medworm.com/index.php?rid=5619135&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22227406%26dopt%3DAbstract Authors: Gu SH, Yeh WL, Young SC, Lin PL, Li S Abstract The prothoracicotropic hormone (PTTH) is a stimulator of ecdysteroidogenesis in prothoracic gland of larval insects. Our recent studies showed that phosphoinositide 3-kinase (PI3K)/Akt signaling was involved in PTTH-stimulated ecdysteroidogenesis by Bombyx mori prothoracic glands. In the present study, downstream signaling of PI3K/Akt was further investigated. Results showed that PTTH rapidly enhanced the phosphorylation of translational repressor 4E-binding protein (4E-BP) and p70 ribosomal protein S6 kinase (S6K), two known downstream signaling targets of the target of rapamycin complex 1 (TORC1). PTTH stimulated 4E-BP phosphorylation in time- and dose-dependent manners. Injection of PTTH into day-6 last instar larvae greatl... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5619135 Sat, 31 Dec 2011 05:00:00 +0100 5619135 http://www.medworm.com/index.php?rid=5576667&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22212826%26dopt%3DAbstract Authors: Alon M, Elbaz M, Ben-Zvi MM, Feldmesser E, Vainstein A, Morin S Abstract The whitefly Bemisia tabaci is a major generalist agricultural pest of field and horticultural crops world-wide. Despite its importance, the molecular bases of defense mechanisms in B. tabaci against major plant secondary defense compounds, such as the phenylpropanoids, remain unknown. Our experimental system utilized transgenic Nicotiana tabacum plants constitutively expressing the PAP1/AtMYB75 transcription factor which activates relatively specifically the phenylpropanoid/flavonoids biosynthetic pathway. Our study used suppression subtractive hybridization (SSH) and cDNA microarray approaches to compare gene expression between B. tabaci adults subjected to wild-type or transgenic plants for 6 h.... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5576667 Wed, 28 Dec 2011 05:00:00 +0100 5576667 http://www.medworm.com/index.php?rid=5576666&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22212827%26dopt%3DAbstract Authors: Merzendorfer H, Kim HS, Chaudhari SS, Kumari M, Specht CA, Butcher S, Brown SJ, Robert Manak J, Beeman RW, Kramer KJ, Muthukrishnan S Abstract Several benzoylphenyl urea-derived insecticides such as diflubenzuron (DFB, Dimilin(®)) are in wide use to control various insect pests. Although this class of compounds is known to disrupt molting and to affect chitin content, their precise mode of action is still not understood. To gain a broader insight into the mechanism underlying the insecticidal effects of benzoylphenyl urea compounds, we conducted a comprehensive study with the model beetle species and stored product pest Tribolium castaneum (red flour beetle) utilizing genomic and proteomic approaches. DFB was added to a wheat flour-based diet at various concentrations and... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5576666 Wed, 28 Dec 2011 05:00:00 +0100 5576666 http://www.medworm.com/index.php?rid=5576665&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22214827%26dopt%3DAbstract Authors: Veenstra JA, Rombauts S, Grbić M Abstract The genome of the spider mite was prospected for the presence of genes coding neuropeptides, neurohormones and their putative G-protein coupled receptors. Fifty one candidate genes were found to encode neuropeptides or neurohormones. These include all known insect neuropeptides and neurohormones, with the exception of sulfakinin, corazonin, neuroparsin and PTTH. True orthologs of adipokinetic hormone (AKH) were neither found, but there are three genes encoding peptides similar in structure to both AKH and the AKH-corazonin-related peptide. We were also unable to identify the precursors for pigment dispersing factor (PDF) or the recently discovered trissin. However, the spider mite probably does have such genes, as we found their p... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5576665 Wed, 28 Dec 2011 05:00:00 +0100 5576665 http://www.medworm.com/index.php?rid=5557924&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22210150%26dopt%3DAbstract Authors: Balczun C, Siemanowski J, Pausch JK, Helling S, Marcus K, Stephan C, Meyer HE, Schneider T, Cizmowski C, Oldenburg M, Höhn S, Meiser CK, Schuhmann W, Schaub GA Abstract Two aspartate protease encoding complementary deoxyribonucleic acids (cDNA) were characterised from the small intestine (posterior midgut) of Triatoma infestans and the corresponding genes were named TiCatD and TiCatD2. The deduced 390 and 393 amino acid sequences of both enzymes contain two regions characteristic for cathepsin D proteases and the conserved catalytic aspartate residues forming the catalytic dyad, but only TiCatD2 possesses an entire C-terminal proline loop. The amino acid sequences of TiCatD and TiCatD2 show 51-58% similarity to other insect cathepsin D-like proteases and, respectively, 88... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5557924 Sat, 24 Dec 2011 05:00:00 +0100 5557924 http://www.medworm.com/index.php?rid=5557925&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22207151%26dopt%3DAbstract Authors: Falabella P, Riviello L, Pascale M, Di Lelio I, Tettamanti G, Grimaldi A, Iannone C, Monti M, Pucci P, Tamburro AM, Deeguileor M, Gigliotti S, Pennacchio F Abstract The innate immune system of insects consists of humoural and cellular responses that provide protection against invading pathogens and parasites. Defence reactions against these latter include encapsulation by immune cells and targeted melanin deposition, which is usually restricted to the surface of the foreign invader, to prevent systemic damage. Here we show that a protein produced by haemocytes of Heliothis virescens (Lepidoptera, Noctuidae) larvae, belonging to XendoU family, generates amyloid fibrils, which accumulate in large cisternae of the rough endoplasmic reticulum and are released upon immune chall... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5557925 Thu, 22 Dec 2011 05:00:00 +0100 5557925 http://www.medworm.com/index.php?rid=5544669&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198472%26dopt%3DAbstract This study employs a functional proteomics approach to identify esterolytic enzymes of the vinegar fly Drosophila melanogaster fat body. One of the fat body carboxylesterases, α-Esterase-7, was selected for mutational analysis by gene targeting to generate a deletion mutant fly. Phenotypic characterization of α-Esterase-7 null mutants and transgenic flies, which overexpress a chimeric α-Esterase-7:EGFP gene, reveals important functions of α-Esterase-7 in insecticide tolerance, lipid metabolism and lifespan control. The presented first deletion mutant of any α-Esterase in the model insect D.melanogaster generated by gene targeting not only provides experimental evidence for the endogenous functions of this gene family. It also offers an entry point for in vivo structure-function analy... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544669 Sat, 17 Dec 2011 05:00:00 +0100 5544669 http://www.medworm.com/index.php?rid=5544674&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198332%26dopt%3DAbstract Authors: Rao XJ, Xu XX, Yu XQ Abstract Insects produce a group of antimicrobial peptides (AMPs) in response to microbial infections. Most AMPs are synthesized as inactive precursors/pro-proteins and require proteolytic processing to generate small active peptides. Here we report identification and functional analysis of two lebocin-related proteins (Leb-B and Leb-C) from the tobacco hornworm, Manduca sexta. The mRNA levels of Leb-B and Leb-C increased significantly in larval fat body and hemocytes after injection of Escherichia coli, Micrococcus luteus and Saccharomyces cerevisiae. Western blotting using rabbit polyclonal antibody to Leb-B showed accumulation of large protein(s) and small peptide(s) in larval hemolymph after microbial injection. This result and the presence of RXXR... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544674 Fri, 16 Dec 2011 05:00:00 +0100 5544674 http://www.medworm.com/index.php?rid=5544671&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198354%26dopt%3DAbstract Authors: Kwon DH, Choi JY, Je YH, Lee SH Abstract The mutations (G228S, A391T and F439W) and duplication of the acetylcholinesterase (AChE) gene (Tuace) are involved in monocrotophos resistance in the two-spotted spider mites, Tetranychus urticae (Kwon et al., 2010a, b). The overexpression of T. urticae AChE (TuAChE) as a result of Tuace duplication was confirmed in several field-collected populations by Western blotting using an AChE-specific antibody. To investigate the effects of each mutation on the insensitivity and fitness cost of AChE, eight variants of TuAChE were expressed in vitro using the baculovirus expression system. Kinetic analysis revealed that the G228S and F439W mutations confer approximately 26-fold and 99-fold increases in the insensitivity to monocrotophos,... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544671 Fri, 16 Dec 2011 05:00:00 +0100 5544671 http://www.medworm.com/index.php?rid=5544670&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198355%26dopt%3DAbstract Authors: Gorman MJ, Sullivan LI, Nguyen TD, Dai H, Arakane Y, Dittmer NT, Syed LU, Li J, Hua DH, Kanost MR Abstract Laccase-2 is a highly conserved multicopper oxidase that functions in insect cuticle pigmentation and tanning. In many species, alternative splicing gives rise to two laccase-2 isoforms. A comparison of laccase-2 sequences from three orders of insects revealed eleven positions at which there are conserved differences between the A and B isoforms. Homology modeling suggested that these eleven residues are not part of the substrate binding pocket. To determine whether the isoforms have different kinetic properties, we compared the activity of laccase-2 isoforms from Tribolium castaneum and Anopheles gambiae. We partially purified the four laccases as recombinant enzymes... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544670 Fri, 16 Dec 2011 05:00:00 +0100 5544670 http://www.medworm.com/index.php?rid=5544677&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22193391%26dopt%3DAbstract Authors: Umemiya-Shirafuji R, Tanaka T, Boldbaatar D, Tanaka T, Fujisaki K Abstract Ticks grow rapidly during blood feeding, and their body weight may ultimately increase 100-fold more than that before feeding. The molecular mechanisms controlling growth during blood feeding in ticks remain largely unknown. The conserved insulin/PI3K/Akt signaling pathway regulates growth and metabolism in eukaryotes. Here, we show evidence for the involvement of Akt in growth during blood feeding in the parthenogenetic strain of the hard tick Haemaphysalis longicornis. We identified a homolog of the Ser/Thr kinase Akt (HlAkt) from the EST database of the H. longicornis embryo. HlAkt cDNA had a 1,590 bp ORF that encodes 529 amino acids with a predicted molecular weight of 60 kDa. HlAkt possesses ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544677 Wed, 14 Dec 2011 05:00:00 +0100 5544677 http://www.medworm.com/index.php?rid=5544675&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22193393%26dopt%3DAbstract Authors: Wu C, Noonin C, Jiravanichpaisal P, Söderhäll I, Söderhäll K Abstract In an attempt to identify genes encoding thioester-containing proteins in the freshwater crayfish, Pacifastacus leniusculus, three different cDNAs were found. A phylogenetic analysis of these proteins indicates that they can be classified into two subfamilies: two alpha-2-macroglobulins (Pl-A2M1, Pl-A2M2) showing a close similarity to shrimp A2M, and one insect TEP-like protein (Pl-TEP). This is the first report of an insect TEP-like protein in a crustacean. Crayfish Pl-A2M1, Pl-A2M2 and Pl-TEP cDNAs encode proteins with 1480, 1586 or 1507 amino acids, respectively. Pl-A2M1, Pl-A2M2 and Pl-TEP have the basic domain structure and functionally important residues for each molecule, and their mRNA was de... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544675 Wed, 14 Dec 2011 05:00:00 +0100 5544675 http://www.medworm.com/index.php?rid=5544672&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198334%26dopt%3DAbstract Authors: Yamaguchi K, Matsumoto H, Ochiai M, Tsuzuki S, Hayakawa Y Abstract Growth rates of immature animals are governed by their feeding activities. A reduction in feeding sometimes causes serious growth retardation in insects; a typical case is often seen in host insects parasitized by a solitary endoparasitoid wasp. However, understanding of the mechanisms underlying the physiological repression of parasitized insects is fragmentary. Here we analyzed brain gene expression of the host common cutworm, Spodoptera litura, parasitized by a solitary endoparasitoid, Microplitis manilae, and identified a novel gene whose expression was significantly enhanced by parasitization. The gene encoded a pre-pro-peptide of a cytokine-like molecule and its expression was observed mainly in nervo... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544672 Wed, 14 Dec 2011 05:00:00 +0100 5544672 http://www.medworm.com/index.php?rid=5544676&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22193392%26dopt%3DAbstract Authors: Schramm K, Vassão DG, Reichelt M, Gershenzon J, Wittstock U Abstract The defensive properties of the glucosinolate-myrosinase system in plants of the order Brassicales have been attributed to the formation of toxic isothiocyanates generated upon tissue damage. Lepidopteran herbivores specialised on brassicaceous plants have been shown to possess biochemical mechanisms preventing the formation of isothiocyanates. Yet, no such mechanisms are known for generalist lepidopterans which also occasionally but successfully feed on plants of the Brassicales. When larvae of Spodopteralittoralis were fed leaves of Arabidopsis thaliana containing [(14)C]4-methylsulfinylbutyl glucosinolate, more than half of the ingested radioactivity was excreted as the unmetabolised corresponding iso... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544676 Tue, 13 Dec 2011 05:00:00 +0100 5544676 http://www.medworm.com/index.php?rid=5544673&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198333%26dopt%3DAbstract Authors: Dong Y, Morton JC, Ramirez JL, Souza-Neto JA, Dimopoulos G Abstract Here we investigated the effect of Beauveria bassiana infection on the survival of Aedesaegypti mosquitoes and the modulation of their susceptibility to dengue virus infection. Application of B. bassiana caused a reduction in the life span of A. aegypti and hindered dengue virus replication in the mosquito midgut. Fungus infection induced the expression a variety anti-microbial and dengue virus restriction factor genes. Transient reverse genetic analyses showed that the JAK-STAT pathway is implicated anti-fungal defense of Aedes mosquitoes. Our data suggest that this B. bassiana-mediated anti-dengue activity is likely to be at least partly indirectly mediated through the activation of the mosquito's ant... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5544673 Tue, 13 Dec 2011 05:00:00 +0100 5544673 http://www.medworm.com/index.php?rid=5526284&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22182589%26dopt%3DAbstract Authors: Kötzler MP, Blank S, Behnken HN, Alpers D, Bantleon FI, Spillner E, Meyer B Abstract Glycans of glycoproteins are often associated with IgE mediated allergic immune responses. Hymenoptera venoms, e.g., carry α1,3-fucosyl residues linked to the proximal GlcNAc of glycoproteins. This epitope, formed selectively by α1,3-fucosyltransferase (FucTA), is xenobiotic and as such highly immunogenic and it also shows cross-reactivity if present on different proteins. Production of post-translationally modified proteins in insect cells is however commonly used and, thus, resulting glycoproteins can carry this highly immunogenic epitope with potentially significant side effects on mammals. To analyze mechanism, specificity and reaction kinetics of the key enzyme, we chose FucTA from... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5526284 Tue, 13 Dec 2011 05:00:00 +0100 5526284 http://www.medworm.com/index.php?rid=5526286&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22178129%26dopt%3DAbstract Authors: Kobayashi I, Tsukioka H, Kômoto N, Uchino K, Sezutsu H, Tamura T, Kusakabe T, Tomita S Abstract RNA interference is one of the most revolutionary tools in the study of gene function, particularly in non-model systems. However, in Bombyx mori, as with many lepidopteran species, attempts at systemic RNAi have had mixed success. Gene identification and phylogenetic analyses suggest that Bombyx has the core RNAi machinery, which is necessary to undergo RNAi as a cellular response. We introduced sid genes from Caenorhabditis elegans into Bombyx BmN4 cells to enhance the uptake of dsRNA and revealed that the SID-1 protein, but not SID-2, has the ability to endow the RNAi effect with the addition of dsRNA to the medium. Observed RNAi effect was dependent on both the levels of si... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5526286 Thu, 08 Dec 2011 05:00:00 +0100 5526286 http://www.medworm.com/index.php?rid=5526285&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22178597%26dopt%3DAbstract Authors: Vandermoten S, Mescher MC, Francis F, Haubruge E, Verheggen FJ Abstract Aphids are important agricultural and forest pests that exhibit complex behaviors elicited by pheromonal signals. The aphid alarm pheromone - of which (E)-β-farnesene is the key (or only) component in most species - plays important roles in mediating interactions among individuals as well as multitrophic interactions among plants, aphids, and aphid natural enemies. Though many important questions remain to be answered, a large body of research has addressed various aspects of the biology, physiology, and ecology of aphid alarm pheromones. Here we review recent advances in our understanding of (a) the identity and composition of aphid alarm signals; (b) their biosynthesis and production; (c) their effe... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5526285 Thu, 08 Dec 2011 05:00:00 +0100 5526285 http://www.medworm.com/index.php?rid=5526288&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22155036%26dopt%3DAbstract Authors: Ahn SJ, Vogel H, Heckel DG Abstract UDP-glycosyltransferases (UGT) catalyze the conjugation of a range of diverse small lipophilic compounds with sugars to produce glycosides, playing an important role in the detoxification of xenobiotics and in the regulation of endobiotics in insects. Recent progress in genome sequencing has enabled an assessment of the extent of the UGT multigene family in insects. Here we report over 310 putative UGT genes identified from genomic databases of eight different insect species together with a transcript database from the lepidopteran Helicoverpa armigera. Phylogenetic analysis of the insect UGTs showed Order-specific gene diversification and inter-species conservation of this multigene family. Only one family (UGT50) is found in all insect... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5526288 Wed, 07 Dec 2011 05:00:00 +0100 5526288 http://www.medworm.com/index.php?rid=5526287&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22155635%26dopt%3DAbstract Authors: Wang HB, Ali SM, Moriyama M, Iwanaga M, Kawasaki H Abstract The trimolter mutants of Bombyx mori have four instead of five larval instars of normal tetramolters. Here, we show that the tetramolter was induced in the recessive trimolter European No.7 mutant (rt-E7) by application of either the juvenile hormone analog (JHA) or 20-hydroxyecdysone (20E). However, treatments with JHA or 20E did not change the number of larval instars of the dominant trimolter Si Chuan mutant (DT-SC). Krüppel-homolog 1 (Kr-h1) is an early JH-response gene that mediates the anti-metamorphic action of JH. In the wing disc of tetramolter B. mori, Kr-h1 RNAs decreased shortly after ecdysis to the fifth instar, while pupal specifier gene, Broad Complex Z1 (BR-Z1) RNAs slightly increased and coincid... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5526287 Tue, 06 Dec 2011 05:00:00 +0100 5526287 http://www.medworm.com/index.php?rid=5526315&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22154754%26dopt%3DAbstract Authors: Tobback J, Boerjan B, Vandersmissen HP, Huybrechts R Abstract In all living organisms, behavior, metabolism and physiology are under the regulation of a circadian clock. The molecular machinery of this clock has been conserved throughout the animal kingdom. Besides regulating the circadian timing of a variety of processes through a central oscillating mechanism in the brain, these circadian clock genes were found to have a function in peripheral tissues in different insects. Here, we provide evidence that the circadian clock genes period (per) and timeless (tim) have a role in the male locust reproduction. A knockdown of either of the two genes has no effect on male sexual maturation or behavior, but progeny output in their untreated female copulation partners is affected.... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5526315 Thu, 01 Dec 2011 05:00:00 +0100 5526315 http://www.medworm.com/index.php?rid=5526313&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22154755%26dopt%3DAbstract This report pertains to the high levels of protein tyrosine phosphorylations (PTP) that occurred later during the growth to differentiation transition because of its novelty and relevance to 20E dependence of adult development. Further analyses demonstrated that both ecdysone receptor (EcR) and ultraspiracle (USP), the two dimerizing partners of the functional ecdysone receptor, are tyrosine phosphorylated coincidental with high PTP. Enhanced PTP during growth to differentiation transition and concomitant tyrosine phosphorylation of EcR and USP was shown to occur in another silkmoth species pointing to the necessity of similar protein tyrosine phosphorylation pathways for adult development. Properly timed increases in tissue protein tyrosine kinase (PTK) activity could explain the enhancem... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5526313 Thu, 01 Dec 2011 05:00:00 +0100 5526313 http://www.medworm.com/index.php?rid=5437205&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22100428%26dopt%3DAbstract Authors: Fonseca FP, Soares-Costa A, Ribeiro AF, Rosa JC, Terra WR, Henrique-Silva F Abstract A cDNA coding for a digestive cathepsin L, denominated Sl-CathL, was isolated from a cDNA library of Sphenophorus levis larvae, representing the most abundant EST (10.49%) responsible for proteolysis in the midgut. The open reading frame of 972bp encodes a preproenzyme similar to midgut cathepsin L-like enzymes in other coleopterans. Recombinant Sl-CathL was expressed in Pichia pastoris, with molecular mass of about 42kDa. The recombinant protein was catalytically activated at low pH and the mature enzyme of 39kDa displayed thermal instability and maximal activity at 37°C and pH 6.0. Immunocytochemical analysis revealed Sl-CathL production in the midgut epithelium and secretion from vesic... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5437205 Sat, 12 Nov 2011 05:00:00 +0100 5437205 http://www.medworm.com/index.php?rid=5437204&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22101251%26dopt%3DAbstract Authors: Figueroa-Teran R, Welch WH, Blomquist GJ, Tittiger C Abstract Ipsdienone (2-methyl-6-methylene-2,7-octadien-4-one) is an important intermediate in the biosynthesis of pheromonal ipsdienol (2-methyl-6-methylene-2,7-octadien-4-ol) and ipsenol (2-methyl-6-methylene-7-octen-4-ol) in male pine engraver beetles, Ips pini (Say). A novel ipsdienol dehydrogenase (IDOLDH) with a pheromone-biosynthetic gene expression pattern was cloned, expressed, functionally characterized, and its cellular localization analyzed. The cDNA has a 762nt ORF encoding a 253 amino acid predicted translation product of 28kDa and pI 5.8. The protein has conserved motifs of the Cp2 subfamily of "classical" short-chain dehydrogenases. Transcript levels were highest in pheromone producing tissue: the anterior... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5437204 Fri, 11 Nov 2011 05:00:00 +0100 5437204 http://www.medworm.com/index.php?rid=5412786&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22079281%26dopt%3DAbstract Authors: Schetelig MF, Milano A, Saccone G, Handler AM Abstract In Tephritidae sex determination is established by orthologs to the Drosophila melanogaster transformer and transformer-2 genes, though the primary signals for sex determination differ. The presence of the Y chromosome in the tephritid species is critical for male differentiation, while the ratio of X chromosomes to autosome ploidy is critical in drosophilids. Here the isolation, expression and function of tra and tra-2 orthologs are described for the agriculturally important tephritid, Anastrepha suspensa, and their possible use in genetically modified organisms for biologically-based pest management. The Astra and Astra-2 genes are highly conserved in structure, regulation and function with respect to those known fro... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5412786 Fri, 04 Nov 2011 04:00:00 +0100 5412786 http://www.medworm.com/index.php?rid=5273043&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21958716%26dopt%3DAbstract In this study, we successfully identified 20-hydroxyecdysone (20E) in first instar nymphs (7 days after hatching) of the scorpion Liocheles australasiae, using tandem mass spectrometry combined with high-performance liquid chromatography (LC/MS/MS). This substance was not found in adults after the fifth stage. Other possible molting hormone candidates such as makisterone A (MaA) and ponasterone A (PoA), both of which are reported to be the molting hormones of a few arthropod species, were not detected in this scorpion. The ligand-receptor binding of 20E and its analogs was quantitatively evaluated against the in vitro-translated molting hormone receptor, the heterodimer of ecdysone receptor (EcR) and the retinoid X receptor (RXR) of L. australasiae (LaEcR/LaRXR). The concentrations of ec... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5273043 Thu, 22 Sep 2011 04:00:00 +0100 5273043 http://www.medworm.com/index.php?rid=5240992&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21933709%26dopt%3DAbstract Authors: Qu M, Yang Q Abstract Insect chitin synthase A (CHSA) catalyzes chitin biosynthesis in tissues that develop from ectoderm. Since only one gene copy encodes CHSA, we hypothesized that CHSA is very likely to exist as isoforms through alternative splicing, and the functions of these isoforms may be tissue-specific. Besides the known alternative splicing exons in the mid-ORF region, we report here the alternative exons (OfCHSA-2a and OfCHSA-2b) of OfCHSA, the chitin synthase A from the lepidopteran pest Ostrinia furnacalis. Sequence analysis of the 5' upstream region of the transcription start site indicated that presences of two independent promoters for controlling the expression of OfCHSA-2a/b. Both OfCHSA-2a and OfCHSA-2b transcripts were preferentially expressed in the ep... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5240992 Wed, 14 Sep 2011 04:00:00 +0100 5240992 http://www.medworm.com/index.php?rid=5225825&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21914479%26dopt%3DAbstract Authors: Mon H, Izumi M, Mitsunobu H, Tatsuke T, Iiyama K, Jikuya H, Lee JM, Kusakabe T Abstract Epigenetic information is encoded in post-translational modifications (PTMs) of histones. Various combinations of these marks contribute to the regulation of chromatin-templated DNA metabolisms. The histone code is gradually translated into biological responses in model organisms. However, in the silkworm, the modifications of histones with unique holocentric chromosomes have not yet been analyzed. TAU-PAGE analysis of the silkworm histone variants H2A, H2B, and H3, separated by RP-HPLC, suggested silkworm specific modification. Detailed mass spectrometry analyses of the peptides derived from the N-terminus of the silkworm H3.2 generated by glutamyl endopeptidase, lysyl endopeptidase, a... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5225825 Sat, 10 Sep 2011 04:00:00 +0100 5225825 http://www.medworm.com/index.php?rid=5225826&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21911060%26dopt%3DAbstract Authors: Suganuma I, Ushiyama T, Yamada H, Iwamoto A, Kobayashi M, Ikeda M Abstract We cloned and characterized a novel Bombyx mori homologue (bm-dronc) of Drosophila melanogaster dronc (dm-dronc), which could encode a polypeptide of 438 amino acid residues. Bm-Dronc shares relatively low amino acid sequence identities of 25% and 26% with Dm-Dronc and Aedes aegypti Dronc (Aa-Dronc), respectively. Bm-Dronc has the sequence QACRG surrounding the catalytic site (C), which is consistent with the QAC(R/Q/G)(G/E) consensus sequence in most caspases but distinct from the sequences PFCRG and SICRG of Dm-Dronc and Aa-Dronc, respectively. Bm-Dronc possesses a long N-terminal prodomain containing a caspase recruitment domain (CARD), a p20 domain and a p10 domain, exhibiting cleavage activitie... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5225826 Thu, 08 Sep 2011 04:00:00 +0100 5225826 http://www.medworm.com/index.php?rid=5215725&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21888974%26dopt%3DAbstract Authors: Kuhn-Nentwig L, Largiadèr CR, Streitberger K, Chandru S, Baumann T, Kämpfer U, Schaller J, Schürch S, Nentwig W Abstract Cupiennius salei single insulin-like growth factor-binding domain protein (SIBD-1), which exhibits an IGFBP N-terminal domain-like profile, was identified in the hemocytes of the spider C.salei. SIBD-1 was purified by RP-HPLC and the sequence determined by a combination of Edman degradation and 5'-3'- RACE PCR. The peptide (8676.08 Da) is composed of 78 amino acids, contains six intrachain disulphide bridges and carries a modified Thr residue at position 2. SIBD-1 mRNA expression was detected by quantitative real-time PCR mainly in hemocytes, but also in the subesophageal nerve mass and muscle. After infection, the SIBD-1 content in the hemocytes dec... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5215725 Fri, 26 Aug 2011 04:00:00 +0100 5215725 http://www.medworm.com/index.php?rid=5189473&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21878389%26dopt%3DAbstract We examined the same compounds on nicotinic acetylcholine receptors in stick insect neurons, which have previously been shown to desensitize in the presence of ACh. Brief U-tube application of 10(-4) M solutions of insecticides for 1 s evoked currents that were much smaller than ACh-evoked currents, and depressed subsequent ACh-evoked currents for several minutes, indicating that the compounds are low-efficacy partial agonists that potently desensitize the receptors. Much lower concentrations of insecticides applied in the bath for longer periods did not activate currents, but inhibited ACh-evoked currents via desensitization of the receptors. Previously described fast- and slowly-desensitizing nACh currents, I(ACh1) and I(ACh2) respectively, were each found to consist of two components ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5189473 Mon, 22 Aug 2011 23:00:00 +0100 5189473 http://www.medworm.com/index.php?rid=5189472&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21878390%26dopt%3DAbstract This study shows that resilin gene and protein sequences are broadly conserved and that crosslinked recombinant resilin proteins share similar mechanical properties from flying to jumping insects. A combined use of degenerate primers and polyclonal sera will likely facilitate characterisation of resilin genes from other insect and invertebrate orders. PMID: 21878390 [PubMed - as supplied by publisher] (Source: Insect Biochemistry and Molecular Biology) Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5189472 Mon, 22 Aug 2011 23:00:00 +0100 5189472 http://www.medworm.com/index.php?rid=5089938&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21807095%26dopt%3DAbstract Authors: Chung H, Boey A, Lumb C, Willoughby L, Batterham P, Daborn PJ Organisms induce the expression of detoxification enzymes such as cytochrome P450s to deal with xenobiotics encountered in the environment. Research using cell culture systems has identified some of the cis-regulatory elements (CREs) and transcription factors involved in the induction of P450 genes in response to xenobiotic challenges. It was recently found that the CREs required for the basal expression of some P450s are distinct from the CREs involved in their induction. How these CREs mediate induction to xenobiotics in a tissue specific manner is not known. In this paper we show that, in Drosophila melanogaster, the induction response of the P450 gene Cyp6g1 to the xenobiotic Phenobarbital (PB) requires the pres... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5089938 Tue, 26 Jul 2011 23:00:00 +0100 5089938 http://www.medworm.com/index.php?rid=5089948&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21802512%26dopt%3DAbstract Authors: Fang Q, Wang L, Zhu Y, Stanley DW, Chen X, Hu C, Ye G Insect host/parasitoid interactions are co-evolved systems in which host defenses are balanced by parasitoid mechanisms to disable or hide from host immune effectors. Although there is a rich literature on these systems, parasitoid immune-disabling mechanisms have not been fully elucidated. Here we report on a newly discovered immune-disabling mechanism in the Pieris rapae/Pteromalus puparum host/parasitoid system. Because venom injections and parasitization suppresses host phagocytosis, we turned attention to the P. rapae scavenger receptor (Pr-SR), posing the hypothesis that P. puparum venom suppresses expression of the host Pr-SR gene. To test our hypothesis, we cloned a full-length cDNA of the Pr-SR. Multiple sequences ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5089948 Thu, 21 Jul 2011 23:00:00 +0100 5089948 http://www.medworm.com/index.php?rid=5089962&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21782023%26dopt%3DAbstract Authors: Kihara F, Niimi T, Yamashita O, Yaginuma T To understand the molecular mechanisms of how 5°C-incubation activates mRNA expression of Hsp70a and Samui genes in Bombyx mori diapause eggs, we first searched the 5'-upstream regions of the Hsp70a and Samui genes for heat shock elements (HSEs) and found two regions [Hsp70aHSE-1 (-95 to -58) and -2 (-145 to -121), and SamuiHSE-1 (-84 to -55) and -2 (-304 to -290)] corresponding to HSEs (repeats of nGAAn and/or nTTCn). We cloned four cDNAs encoding heat shock factor (HSF)-a2 (627 amino acids), -b (685 aa), -c (682 aa) and -d (705 aa), which were produced by alternative splicing. When we exposed diapause eggs to 5°C beginning at 2 day post-oviposition to break diapause, HSFd mRNA only increased after chilling for 6-8 days, a patt... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5089962 Sun, 17 Jul 2011 23:00:00 +0100 5089962 http://www.medworm.com/index.php?rid=5039095&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21763770%26dopt%3DAbstract Authors: Aguirre SA, Fruttero LL, Leyria J, Defferrari MS, Pinto PM, Settembrini BP, Rubiolo ER, Carlini CR, Canavoso LE In this work, we have explored the biochemical changes characterizing the transition from vitellogenesis to follicular atresia, employing the hematophagous insect vector Dipetalogaster maxima as a model. Standardized insect rearing conditions were established to induce a gradual follicular degeneration stage by depriving females of blood meal during post-vitellogenesis. For the studies, hemolymph and ovaries were sampled at representative days of pre-vitellogenesis, vitellogenesis and early and late follicular atresia. When examined by scanning electron microscopy, ovarioles at the initial stage of atresia were small but still showed some degree of asynchronism, a fe... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5039095 Wed, 06 Jul 2011 23:00:00 +0100 5039095 http://www.medworm.com/index.php?rid=5039096&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21742031%26dopt%3DAbstract Authors: Vuerinckx K, Verlinden H, Lindemans M, Broeck JV, Huybrechts R Following a reverse pharmacology approach, we identified an allatotropin-like peptide receptor in Tribolium castaneum. Allatotropins are multifunctional neuropeptides initially isolated from the tabacco hornworm, Manduca sexta. They have been shown to be myoactive, to be cardio-acceleratory, to inhibit active ion transport, to stimulate juvenile hormone production and release and to be involved in the photic entrainment of the circadian clock. A tissue distribution analysis of the T. castaneum allatotropin-like peptide receptor by means of qRT-PCR revealed a prominent sexual dimorphism, the transcript levels being significantly higher in the male fat body and reproductive system. The endogenous ligand of the recep... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5039096 Thu, 30 Jun 2011 23:00:00 +0100 5039096 http://www.medworm.com/index.php?rid=5039097&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21736942%26dopt%3DAbstract We describe a transcriptome of OFE of the triatomine bug Rhodnius prolixus, a vector of Chagas disease, to increase our knowledge of the role of FE in egg development. Random clones were sequenced from a cDNA library of different stages of follicle development. The transcriptome showed high commitment to transcription, protein synthesis, and secretion. The most abundant cDNA was a secreted (S) small, proline-rich protein with maximal expression in the vitellogenic follicle, suggesting a role in oocyte maturation. We also found Rp45, a chorion protein already described, and a putative chitin-associated cuticle protein that was an eggshell component candidate. Six transcripts coding for proteins related to the unfolded-protein response (UPR) by were chosen and their expression analyzed. Surp... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=5039097 Mon, 27 Jun 2011 23:00:00 +0100 5039097 http://www.medworm.com/index.php?rid=4997066&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21699978%26dopt%3DAbstract Authors: Horodyski FM, Verlinden H, Filkin N, Vandersmissen HP, Fleury C, Reynolds SE, Kai ZP, Broeck JV Manduca sexta allatotropin (Manse-AT) is a multifunctional neuropeptide whose actions include the stimulation of juvenile hormone biosynthesis, myotropic stimulation, cardioacceleratory functions, and inhibition of active ion transport. Manse-AT is a member of a structurally related peptide family that is widely found in insects and also in other invertebrates. Its precise role depends on the insect species and developmental stage. In some lepidopteran insects including M. sexta, structurally-related AT-like (ATL) peptides can be derived from alternatively spliced mRNAs transcribed from the AT gene. We have isolated a cDNA for an AT receptor (ATR) from M. sexta by a PCR-based appr... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4997066 Mon, 13 Jun 2011 23:00:00 +0100 4997066 http://www.medworm.com/index.php?rid=4997067&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21689750%26dopt%3DAbstract Authors: Revuelta L, Ortego F, Díaz-Ruíz JR, Castañera P, Tenllado F, Hernández-Crespo P The Colorado potato beetle (CPB), Leptinotarsa decemlineata is an important economic pest of potato worldwide. Resistance to organophosphates and carbamates in CPB has been associated in some cases to point mutations in the acetylcholinesterase (AChE) gene Ldace2, an orthologue of Drosophila melanogaster Dmace2. In this paper we report cloning and sequencing of Ldace1, an orthologue of Anopheles gambiae Agace1 that was previously unknown in CPB. The Ldace1 coding enzyme contains all residues conserved in a functionally active AChE. Ldace1 is expressed at higher levels (between 2- and 11-fold) than Ldace2 in embryos, in the four larval instars and in adults. Specific interference of Ldace1 by me... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4997067 Sat, 11 Jun 2011 23:00:00 +0100 4997067 http://www.medworm.com/index.php?rid=4947022&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664464%26dopt%3DAbstract Authors: Kaneko Y, Furuta K, Kuwano E, Hiruma K Ethyl 4-[(S)-2-benzylhexyloxy)]benzoate (KF-13S), derived from ethyl 4-[2-(tert-butylcarbonyloxy)butoxy]benzoate (ETB), has strong anti-juvenile hormone (JH) activity which causes precocious metamorphosis in Bombyx mori, and the mode of action of this compound was studied. Application of KF-13S inhibited JH biosynthesis by the corpora allata (CA) in a reversible manner, and in vitro culture experiments showed that this inhibition was due to the direct action of this compound on the CA. When mRNA expression of the JH biosynthetic enzymes were studied, KF-13S strongly suppressed those of HMG Co-A synthase and HMG Co-A reductase. mRNA levels of other mevalonate enzymes and JH acid O-methyltransferase were also suppressed but were less sensi... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4947022 Wed, 01 Jun 2011 23:00:00 +0100 4947022 http://www.medworm.com/index.php?rid=4947024&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21651981%26dopt%3DAbstract Authors: Ding BJ, Liénard MA, Wang HL, Zhao CH, Löfstedt C The winter moth (Operophtera brumata L., Lepidoptera: Geometridae) utilizes a single hydrocarbon, 1,Z3,Z6,Z9-nonadecatetraene, as its sex pheromone. We tested the hypothesis that a fatty acid precursor, Z11,Z14,Z17,19-nonadecanoic acid, is biosynthesized from α-linolenic acid, through chain elongation by one 2-carbon unit, and subsequent methyl-terminus desaturation. Our results show that labeled α-linolenic acid is indeed incorporated into the pheromone component in vivo. A fatty-acyl-CoA desaturase gene that we found to be expressed in the abdominal epidermal tissue, the presumed site of biosynthesis for type II pheromones, was characterized and expressed heterologously in a yeast system. The transgenic yeast expressing ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4947024 Sun, 29 May 2011 23:00:00 +0100 4947024 http://www.medworm.com/index.php?rid=4947023&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21658450%26dopt%3DAbstract Authors: Ratcliffe NA, Mello CB, Garcia ES, Butt TM, Azambuja P In this overview, some of the more significant recent developments in bioengineering natural products from insects with use or potential use in modern medicine are described, as well as in utilisation of insects as models for studying essential mammalian processes such as immune responses to pathogens. To date, insects have been relatively neglected as sources of modern drugs although they have provided valuable natural products, including honey and silk, for at least 4-7000 years, and have featured in folklore medicine for thousands of years. Particular examples of Insect Folk Medicines will briefly be described which have subsequently led through the application of molecular and bioengineering techniques to the developme... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4947023 Sun, 29 May 2011 23:00:00 +0100 4947023 http://www.medworm.com/index.php?rid=4947032&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21640822%26dopt%3DAbstract Authors: Burton MJ, Mellor IR, Duce IR, Davies TG, Field LM, Williamson MS Knockdown resistance (kdr) in insects, caused by inherited nucleotide polymorphisms in the voltage-gated sodium channel (VGSC) gene, is a major threat to the efficacy of pyrethroid insecticides. Classic kdr, resulting from an L1014F substitution in the VGSC is now present in numerous pest species. Two other substitutions at the L1014 locus have also been reported, L1014S and L1014H. Here we have used expression of L1014 modified Drosophila para VGSCs in Xenopus oocytes with two-electrode voltage clamp to characterise all three mutations. The mutations L1014F and L1014H caused significant depolarizing shifts in the half activation voltage (V(50,act)) from -17.3mV (wild-type) to -13.1 and -13.5mV respectively, ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4947032 Thu, 26 May 2011 23:00:00 +0100 4947032 http://www.medworm.com/index.php?rid=4947031&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21640823%26dopt%3DAbstract We present complete sequences of the mitochondrial genomes for two important mosquitoes, Aedes aegypti and Culex quinquefasciatus, that are major vectors of dengue virus and lymphatic filariasis, respectively. The A. aegypti mitochondrial genome is 16,655 bp in length and that of C.quinquefasciatus is 15,587 bp, yet both contain 13 protein coding genes, 22 transfer RNA (tRNA) genes, one 12S ribosomal RNA (rRNA) gene, one 16S rRNA gene and a control region (CR) in the same order. The difference in the genome size is due to the difference in the length of the control region. We also analyzed insertions of nuclear copies of mtDNA-like sequences (NUMTs) in a comparative manner between the two mosquitoes. The NUMT sequences occupy ∼0.008% of the A. aegypti genome and ∼0.001% of the C. ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4947031 Thu, 26 May 2011 23:00:00 +0100 4947031 http://www.medworm.com/index.php?rid=4947030&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21641996%26dopt%3DAbstract Authors: Zhang S, Gunaratna RT, Zhang X, Najar F, Wang Y, Roe B, Jiang H Although Manduca sexta has significantly contributed to our knowledge on a variety of insect physiological processes, the lack of its genome sequence hampers the large-scale gene discovery, transcript profiling, and proteomic analysis in this biochemical model species. Here we report our implementation of the RNA-Seq cDNA sequencing approach based on massively parallel pyrosequencing, which allows us to categorize transcripts based on their relative abundances and to discover process- or tissue-specifically regulated genes simultaneously. We obtained 1,821,652 reads with an average length of 289 bp per read from fat body and hemocytes of naïve and microbe-injected M. sexta larvae. After almost all (92.1%) of th... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4947030 Thu, 26 May 2011 23:00:00 +0100 4947030 http://www.medworm.com/index.php?rid=4947029&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21645617%26dopt%3DAbstract Authors: Huang J, Wang Y, Raghavan S, Feng S, Kiesewetter K, Wang J Drosophila Down syndrome cell adhesion molecule (Dscam) potentially produces more than 150,000 cell adhesion molecules that share two alternative transmembrane/juxtamembrane (TM) domains, which dictate the dendrite versus axon subcellular distribution and function of different Dscam isoforms. Vertebrate genomes contain two closely related genes, DSCAM and DSCAM-Like1 (DSCAML1), which do not have extensive alternative splicing. We investigated the functional conservation between invertebrate Dscams and vertebrate DSCAMs by cross-species rescue assays and found that human DSCAM and DSCAML1 partially, but substantially, rescued the larval lethality of Drosophila Dscam mutants. Interestingly, both human DSCAM and DSCAML1 w... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4947029 Thu, 26 May 2011 23:00:00 +0100 4947029 http://www.medworm.com/index.php?rid=4947028&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21645618%26dopt%3DAbstract In this study we provide a molecular and biochemical identification of two arylalkylamine N-acetyltransferases (aaNAT) from Aedes aegypti mosquitoes. N-acetyldopamine, the enzyme product of aaNAT, was detected in Ae. aegypti, indicating the presence of an aaNAT in this mosquito. A BLAST search of the Ae. aegypti genome, using sequence information from an activity-verified Drosophila aaNAT, identified thirteen putative aaNAT sequences sharing 13-48% sequence identity with the Drosophila enzyme. Eight of the thirteen putative aaNAT proteins were expressed using a bacterial expression system. Screening of purified recombinant proteins against 5-hydroxytryptamine, dopamine, methoxytryptamine, norepinephrine, octopamine, tryptamine, and tyramine substrates, established that two of the putative ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4947028 Thu, 26 May 2011 23:00:00 +0100 4947028 http://www.medworm.com/index.php?rid=4851349&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21571068%26dopt%3DAbstract CONCLUSION: The results of this study lead us to believe that LmPSTI plays an important role in controlling the proteolytic activity in the digestive system of L. migratoria. These findings provide new evidence for the existence of an ancient protective mechanism in metazoan digestive systems and open new perspectives for the study of autophagy-related diseases in the digestive tract. PMID: 21571068 [PubMed - as supplied by publisher] (Source: Insect Biochemistry and Molecular Biology) Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4851349 Sat, 07 May 2011 23:00:00 +0100 4851349 http://www.medworm.com/index.php?rid=4851348&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21571069%26dopt%3DAbstract In this study, we isolated a total of 20 full-length cDNA clones that cover the entire coding region of the DSC1 gene from adults of Drosophila melanogaster by reverse transcription-polymerase chain reaction. Sequence analysis of the 20 clones revealed nine optional exons, four of which contain in-frame stop codons; and 13 potential A-to-I RNA editing sites. The 20 clones can be grouped into eight splice types and represent 20 different transcripts because of unique RNA editing. Three variants generated DSC1 currents when expressed in Xenopus oocytes. Like the BSC1 channel, all three functional DSC1 channels are permeable to Ca(2+) and Ba(2+), and also to Na(+) in the absence of external Ca(2+). Furthermore, the DSC1 channel is insensitive to tetrodotoxin, a potent and specific sodium chan... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4851348 Fri, 06 May 2011 23:00:00 +0100 4851348 http://www.medworm.com/index.php?rid=4851347&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21571070%26dopt%3DAbstract Authors: Pérez MM, Sabio G, Badaracco A, Quesada-Allué LA The present report shows a partial biochemical characterization and life cycle expression of N-β-alanyldopamine hydrolase (Tan protein) in Ceratitiscapitata and Drosophilamelanogaster. This enzyme catalyzes the hydrolysis of N-β-alanyldopamine (NBAD), the main tanning precursor of insect brown cuticles. It also plays an important role in the metabolism of brain neurotransmitters, recycling dopamine and histamine. In contrast to NBAD-synthase, Tan is expressed constitutively in epidermis and does not respond directly to microbial challenge. Immunodetection experiments showed the novel localization of NBAD-hydrolase in the embryo central neural system and in different regions of the adult brain, in addition to optic lobes. W... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4851347 Fri, 06 May 2011 23:00:00 +0100 4851347 http://www.medworm.com/index.php?rid=4851346&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21575721%26dopt%3DAbstract Authors: Bao B, Hong B, Feng QL, Xu WH The transcription factor fork head (FoxA) plays important roles in development and metabolism. Here, we cloned a fork head gene in Helicoverpa armigera, and found that the fork head protein is mainly located in the nucleus. This fork head gene belongs to the FoxA subfamily of the Fox transcription factors. The diapause hormone and pheromone biosynthesis-activating neuropeptide (DH-PBAN), which are two well-documented insect neuropeptides that regulate insect development and pheromone biosynthesis, are encoded by a single mRNA. In the present study, fork head was shown to bind strongly to the promoter of H. armigera DH-PBAN gene, and regulate its promoter activity. Furthermore, the effect of SUMOylation of the FH protein on the regulation of Har-D... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4851346 Fri, 06 May 2011 23:00:00 +0100 4851346 http://www.medworm.com/index.php?rid=4851350&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21554954%26dopt%3DAbstract Authors: Nouzova M, Edwards MJ, Mayoral JG, Noriega FG Juvenile hormone (JH) is a key regulator of metamorphosis and ovarian development in mosquitoes. Adult female Aedes aegypti mosquitoes show developmental and dynamically regulated changes of JH synthesis. Newly emerged females have corpora allata (CA) with low biosynthetic activity, but they produce high amounts of JH a day later; blood feeding results in a striking decrease in JH synthesis, but the CA returns to a high level of JH synthesis three days later. To understand the molecular bases of these dynamic changes we combined transcriptional studies of 11 of the 13 enzymes of the JH pathway with a functional analysis of JH synthesis. We detected up to a 1000-fold difference in the levels of mRNA in the CA among the JH biosynthet... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4851350 Mon, 02 May 2011 23:00:00 +0100 4851350 http://www.medworm.com/index.php?rid=4851351&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21554953%26dopt%3DAbstract Authors: Zhao P, Lu Z, Strand MR, Jiang H Phenoloxidase (PO) and its activation system are implicated in several defense responses of insects. Upon wounding or infection, inactive prophenoloxidase (proPO) is converted to active PO through a cascade of serine proteases and their homologs. PO generates reactive compounds such as 5,6-dihydroxyindole (DHI), which have a broad-spectrum antibacterial and antifungal activity. Here we report that DHI and its spontaneous oxidation products are also active against viruses and parasitic wasps. Preincubation of a baculovirus stock with 1.25 mM DHI for 3 h near fully disabled recombinant protein production. The LC(50) for lambda bacteriophage and eggs of the wasp Microplitis demolitor were 5.6 ± 2.2 and 111.0 ± 1.6 μM, respectively. The t... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4851351 Sat, 30 Apr 2011 23:00:00 +0100 4851351 http://www.medworm.com/index.php?rid=4851352&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21549193%26dopt%3DAbstract Authors: Shao X, Lu H, Bao H, Xu X, Liu Z, Li Z Neonicotinoid insecticides, such as imidacloprid, are selective agonists of the insect nicotinic acetylcholine receptors (nAChRs) with -NO(2) or -CN group in trans-configuration. Previously we reported the excellent insecticidal activity of a series of nitroconjugated neonicotinoids with -NO(2) or -CN group in cis-configuration by replacing nitromethylene pharmacophore with a nitroconjugated system. To understand the action mode of these nitroconjugated neonicotinoids, a representative member IPPA152201 was chosen to perform toxicity and pharmacology studies. IPPA152201 showed a comparable toxicity with imidacloprid against Nilaparvatalugens in a susceptible strain and had no significant cross-resistance in an imidacloprid resistant strai... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4851352 Thu, 28 Apr 2011 23:00:00 +0100 4851352 http://www.medworm.com/index.php?rid=4798186&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21536128%26dopt%3DAbstract In this study, we report the establishment of the binary Gal4/UAS system for the yellow fever mosquito Aedes aegypti. We utilized the 1.8-kb 5' upstream region of the vitellogenin gene (Vg) to genetically engineer mosquito lines with the Vg-Gal4 activator and established UAS-EGFP responder transgenic mosquito lines to evaluate the binary Gal4/UAS system. The results show that the Vg-Gal4 driver leads to a high level of tissue-, stage- and sex-specific expression of the EGFP reporter in the fat body of Vg-Gal4/UAS-EGFP hybrids after blood-meal activation. In addition, the applicability of this system to study hormonal regulation of gene expression was demonstrated in in vitro organ culture experiments in which the EGFP reporter was highly activated in isolated fat bodies of previtellogenic... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4798186 Thu, 28 Apr 2011 23:00:00 +0100 4798186 http://www.medworm.com/index.php?rid=4798187&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21530657%26dopt%3DAbstract Authors: Ilg T, Cramer J, Lutz J, Noack S, Schmitt H, Williams H, Newton T Acetylcholinesterase (AChE, EC3.1.1.7.) is the molecular target for the carbamate and organophosphate pesticides that are used to combat parasitic arthropods. In this paper we report the functional heterologous expression of AChE from Lucilia cuprina (the sheep blowfly) in HEK293 cells. We show that the expressed enzyme is cell-surface-exposed and possesses a glycosyl-phosphatidylinositol membrane anchor. The substrates acetyl-, propionyl- and butyrylthiocholine (AcTC, PropTC, ButTC), and also 11 further thiocholine and homo-thiocholine derivatives were chemically synthesized to evaluate and compare their substrate properties in L. cuprina AChE and recombinant human AChE. The Michaelis-Menten constants K(M) for... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4798187 Fri, 22 Apr 2011 23:00:00 +0100 4798187 http://www.medworm.com/index.php?rid=4798185&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21540111%26dopt%3DAbstract In this study, we discovered and isolated a Cyp9m10 haplotype closely related to this duplicated Cyp9m10 haplotype from JHB, a strain used for the recent genome project for this mosquito species. The isolated haplotype (JHB-NIID-B haplotype) shared the same insertion of a transposable element upstream of the coding region with JPal-per strain but not duplicated. The JHB-NIID-B haplotype was considered to have diverged from the JPal-per lineage just before the duplication event. Cyp9m10 was moderately overexpressed in larvae with the JHB-NIID-B haplotype. The overexpressions in JHB-NIID-B and JPal-per haplotypes were developmentally regulated in similar pattern indicating both haplotypes share a common cis-acting mutation responsible for the overexpressions. The isolated moderately overexpr... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4798185 Fri, 22 Apr 2011 23:00:00 +0100 4798185 http://www.medworm.com/index.php?rid=4745376&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21501685%26dopt%3DAbstract Authors: Wondji CS, Dabire RK, Tukur Z, Irving H, Djouaka R, Morgan JC Growing problems of pyrethroid resistance in Anopheles funestus have intensified efforts to identify alternative insecticides. Many agrochemicals target the GABA receptors, but cross-resistance from dieldrin resistance may preclude their introduction. Dieldrin resistance was detected in An. funestus populations from West (Burkina Faso) and central (Cameroon) Africa, but populations from East (Uganda) and Southern Africa (Mozambique and Malawi) were fully susceptible to this insecticide. Partial sequencing of the dieldrin target site, the γ-aminobutyric acid (GABA) receptor, identified two amino acid substitutions, A296S and V327I. The A296S mutation has been associated with dieldrin resistance in other species. The... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745376 Fri, 08 Apr 2011 23:00:00 +0100 4745376 http://www.medworm.com/index.php?rid=4745379&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21497652%26dopt%3DAbstract Authors: Powell GF, Ward DA, Prescott MC, Spiller DG, White MR, Turner PC, Earley FG, Phillips J, Rees HH Pyridalyl is a recently discovered insecticide that exhibits high insecticidal activity against Lepidoptera and Thysanoptera. Pyridalyl action requires cytochrome P450 activity, possibly for production of a bioactive derivative, Pyridalyl metabolism being prevented by general P450 inhibitors. Apoptosis is apparently not involved in the cytotoxicity. Continuous culture of Spodoptera frugiperda Sf21 cells in sub-lethal doses of Pyridalyl, results in a Pyridalyl-resistant cell line. Probing the molecular action of Pyridalyl by comparison of the proteomes of Pyridalyl-resistant and -susceptible cell lines, revealed differential expression of a number of proteins, including the up-regul... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745379 Thu, 07 Apr 2011 23:00:00 +0100 4745379 http://www.medworm.com/index.php?rid=4745378&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21497653%26dopt%3DAbstract Authors: Huang N, Clem RJ, Rohrmann GF Complementary DNAs encoding homologs of the tumor suppressor gene, p53, were characterized from two lepidopteran insects, Bombyx mori (Bm) and Spodoptera frugiperda (Sf). They encoded predicted proteins of 368 (41.2 kDa) (Bm) and 374 (42.5 kDa) (Sf) amino acids. The sequences shared 44% amino acid and 60% nucleotide sequence identity with each other, but exhibited less than 20% amino acid and 46% nucleotide sequence identity to Drosophila melanogaster p53. Despite the sequence diversity, conserved amino acids involved in DNA and zinc binding were present in the lepidopteran sequences. Expression of Sfp53-induced apoptosis in S. frugiperda cells, and antiserum made against recombinant Sfp53 recognized a protein whose abundance increased after tr... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745378 Thu, 07 Apr 2011 23:00:00 +0100 4745378 http://www.medworm.com/index.php?rid=4745377&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21501684%26dopt%3DAbstract This report is the first to show involvement of the p38 MAPK pathway in the negative regulation of AMP production in a mosquito. PMID: 21501684 [PubMed - as supplied by publisher] (Source: Insect Biochemistry and Molecular Biology) Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745377 Thu, 07 Apr 2011 23:00:00 +0100 4745377 http://www.medworm.com/index.php?rid=4745380&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21496486%26dopt%3DAbstract In this study, we analyzed promoter elements of the sericin-1 gene (ser1) in vivo by introducing reporter constructs into silk glands via gene gun technology. The region from -1602 to +47 was sufficient to induce MSG-specific expression. The 5' deletion mutants showed a three-step decrease in promoter activity with the key sequences located between -1362 and -1250, -201 and -116, and -115 and -37. We detected a tissue- and stage-specific factor complex (MSG-intermolt-specific complex: MIC) bound to the sequence elements around the -1350, -320, -180, and -70 regions. A mutation in the -70 region, which inhibits MIC-binding, diminished almost all promoter activity, while another mutation that did not inhibit MIC-binding showed no effect on promoter activity. The results suggest ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745380 Wed, 06 Apr 2011 23:00:00 +0100 4745380 http://www.medworm.com/index.php?rid=4745382&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21477651%26dopt%3DAbstract Authors: Humann FC, Hartfelder K In highly eusocial insects, such as the honey bee, Apis mellifera, the reproductive bias has become embedded in morphological caste differences. These are most expressively denoted in ovary size, with adult queens having large ovaries consisting of 150-200 ovarioles each, while workers typically have only 1-20 ovarioles per ovary. This morphological differentiation is a result of hormonal signals triggered by the diet change in the third larval instar, which eventually generate caste-specific gene expression patterns. To reveal these we produced differential gene expression libraries by Representational Difference Analysis (RDA) for queen and worker ovaries in a developmental stage when cell death is a prominent feature in the ovarioles of workers, wher... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745382 Mon, 04 Apr 2011 23:00:00 +0100 4745382 http://www.medworm.com/index.php?rid=4745381&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21477652%26dopt%3DAbstract Authors: Andersen SO Fifty years ago it was concluded that the highly elastic cuticular protein, resilin, is devoid of secondary structure and that the peptide chains are randomly coiled and easily and reversibly deformed. These properties indicate that resilin is an intrinsically disordered protein and suggest that also other cuticular proteins may contain disordered regions. Amino acid sequences are now available for cuticular proteins from many insect species, and several programs have been developed to predict the probability for a given protein to contain disordered regions. The present paper describes the results obtained when the predictors are applied to various types of cuticular proteins from several insects. The results suggest that most cuticular proteins contain shorter or... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745381 Mon, 04 Apr 2011 23:00:00 +0100 4745381 http://www.medworm.com/index.php?rid=4745383&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21459142%26dopt%3DAbstract Authors: Yoshizawa Y, Sato R, Tsuchihara K, Ozaki K, Mita K, Asaoka K, Taniai K Expressed sequence tags (ESTs) of the maxillary galea of the silkworm were analyzed to identify proteins involved in food selection systems. From the 1251 redundant genes of the ESTs, we identified 7 odorant-binding protein-like genes (bmObpL), 6 takeout-like genes (bmToL), and 6 chemosensory protein genes (bmCsp). Quantitative RT-PCR analysis indicated that bmObpL1, bmObpL2, bmObpL3, bmObpL5, bmToL1, bmToL3, and bmorCsp15 were predominantly expressed in the larval oral appendages, such as the maxilla, labrum, labium and antenna. Immunocytochemical analysis indicated that the proteins of bmObpL1, bmObpL3, and bmToL1 were localized in the gustatory chemosensilla on the maxillary galea and olfactory sensilla ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745383 Wed, 30 Mar 2011 23:00:00 +0100 4745383 http://www.medworm.com/index.php?rid=4745387&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21440063%26dopt%3DAbstract Authors: Ratzka C, Liang C, Dandekar T, Gross R, Feldhaar H Numerous insect species harbor mutualistic endosymbionts that play a role in nutrient cycling or confer other fitness benefits to their hosts. Insect hosts face the problem of having to maintain such mutualistic bacteria while staging an immune response towards pathogens upon infection. In addition, hosts may regulate the number of endosymbionts present in their tissues via the innate immune system. Camponotus floridanus ants harbor the obligate endosymbiont Blochmannia floridanus in specialized midgut cells and ovaries. We identified genes transcriptionally induced in response to septic injury by suppression subtractive hybridization (SSH). Among these were genes involved in pathogen recognition (e.g. GNBP), signal transducti... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745387 Tue, 29 Mar 2011 23:00:00 +0100 4745387 http://www.medworm.com/index.php?rid=4745386&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21457781%26dopt%3DAbstract Authors: Xu Y, Fu Q, Li S, He N The patterning of embryos in early stages is a critical process for embryo development. In order to understand the molecular mechanism of early embryogenesis in silkworm, 2-DE combined with MALDI-TOF-MS technologies were used to analyze the proteins from diapause-destined eggs at the germ-band formation stage. From over 1000 spots, 93 were selected for analysis and data were obtained from 59 revealing 42 proteins. Gene Ontology annotation showed these proteins were involved in several biological processes at the germ-band formation stage, including cell stress response and protein folding, cell growth and migration, termination of diapause, and nutrition storage. Prominent among them was a new 80 kDa protein, named Bombyx mori egg protein 80 (BmEP80). B... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745386 Tue, 29 Mar 2011 23:00:00 +0100 4745386 http://www.medworm.com/index.php?rid=4745385&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21457782%26dopt%3DAbstract Authors: Meyer JM, Ejendal KF, Watts VJ, Hill CA Advancements in tick neurobiology may impact the development of acaricides to control those species that transmit human and animal diseases. Here, we report the first cloning and pharmacological characterization of two neurotransmitter binding G protein-coupled receptors in the Lyme disease (blacklegged) tick, Ixodes scapularis. The genes IscaGPRdop1 and IscaGPRdop2 were identified in the I. scapularis genome assembly and predicted as orthologs of previously characterized D(1)-like dopamine receptors in the fruit fly Drosophila melanogaster and honeybee Apis mellifera. Heterologous expression in HEK 293 cells demonstrated that each receptor functioned as a D(1)-like dopamine receptor because significant increases in levels of intracellu... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745385 Tue, 29 Mar 2011 23:00:00 +0100 4745385 http://www.medworm.com/index.php?rid=4745384&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21457783%26dopt%3DAbstract Authors: Provost B, Jouan V, Hilliou F, Delobel P, Bernardo P, Ravallec M, Cousserans F, Wajnberg E, Darboux I, Fournier P, Strand MR, Volkoff AN The Polydnaviridae is a family of double-stranded DNA viruses that are symbionts of parasitoid wasps. The family is currently divided into two genera, the Ichnovirus (IV) and Bracovirus (BV), which are associated with wasps in the families Ichneumonidae and Braconidae, respectively. IVs and BVs have similar immunosuppressive and developmental effects on parasitized hosts but their encapsidated genomes largely encode different genes. To assess whether IV and BV infection has similar or disparate effects on the transcriptome of shared hosts, we characterized the effects of Hyposoter didymator Ichnovirus (HdIV) and Microplitis demolitor Bracovir... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4745384 Tue, 29 Mar 2011 23:00:00 +0100 4745384 http://www.medworm.com/index.php?rid=4635276&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21426938%26dopt%3DAbstract In this study, we examined the effect of BTG 502 on wild-type and mutant cockroach sodium channels expressed in Xenopus oocytes. Toxin competition experiments confirmed that BTG 502 antagonizes the action of BTX and possibly shares a common receptor site with BTX. However, unlike BTX which causes persistent activation of sodium channels, BTG 502 reduces the amplitude of peak sodium current. A previous study showed that BTG 502 was more toxic to pyrethroid-resistant house flies possessing a super-kdr (knockdown resistance) mechanism than to pyrethroid-susceptible house flies. However, we found that the cockroach sodium channels carrying the equivalent super-kdr mutations (M918T and L1014F) were not more sensitive to BTG 502 than the wild-type channel. Instead, a kdr mutation, F1519I, which ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4635276 Sat, 19 Mar 2011 00:00:00 +0100 4635276 http://www.medworm.com/index.php?rid=4635275&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21426939%26dopt%3DAbstract Authors: Perry T, Batterham P, Daborn PJ Identifying insecticide resistance mechanisms is paramount for pest insect control, as the understandings that underpin insect control strategies must provide ways of detecting and managing resistance. Insecticide resistance studies rely heavily on detailed biochemical and genetic analyses. Although there have been many successes, there are also many examples of resistance that still challenge us. As a precursor to rational pest insect control, the biology of the insect, within the contexts of insecticide modes of action and insecticide metabolism, must be well understood. It makes sense to initiate this research in the best model insect system, Drosophila melanogaster, and translate these findings and methodologies to other insects. Here we exp... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4635275 Sat, 19 Mar 2011 00:00:00 +0100 4635275 http://www.medworm.com/index.php?rid=4635274&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21426940%26dopt%3DAbstract Authors: Hanin O, Azrielli A, Zakin V, Applebaum S, Rafaeli A Sex pheromone production in the night flying female moth, Helicoverpa armigera is under neuroendocrine control due to the timely release of Pheromone Biosynthesis-Activating Neuropeptide (PBAN). Males orient to the females by upwind anemotaxis which usually leads to a successful mating. During copulation insect males transfer seminal peptides, produced in Male Accessory Glands (MAGs) which are implicated in post-mating behavioral changes of the females. These changes include the termination of pheromone biosynthesis and thus females do not re-mate. In previous studies we showed that synthetic Drosophila melanogaster Sex Peptide (DrmSP), which is responsible for terminating receptivity in female flies, can terminate PBAN-stim... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4635274 Sat, 19 Mar 2011 00:00:00 +0100 4635274 http://www.medworm.com/index.php?rid=4635277&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21419847%26dopt%3DAbstract In this study, a Cht5 gene cluster consisting of five different chitinase-like genes (AgCht5-1, AgCht5-2, AgCht5-3, AgCht5-4 and AgCht5-5) was identified by a bioinformatics search of the genome of Anopheles gambiae. The gene models were confirmed by cloning and sequencing of the corresponding cDNAs and gene expression profiles during insect development were determined. All of these genes are found in a single cluster on chromosome 2R. Their open reading frames (ORF) range from 1227 to 1713 bp capable of encoding putative proteins ranging in size from 409 to 571 amino acids. The identities of their cDNA sequences range from 52 to 66%, and the identities of their deduced amino acid sequences range from 38 to 53%. There are four introns for AgCht5-1, two for AgCht5-2 and AgCht5-3, only one f... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4635277 Wed, 16 Mar 2011 00:00:00 +0100 4635277 http://www.medworm.com/index.php?rid=4635279&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21396445%26dopt%3DAbstract Authors: Moraes J, Arreola R, Cabrera N, Saramago L, Freitas D, Masuda A, da Silva Vaz I, Tuena de Gomez-Puyou M, Perez-Montfort R, Gomez-Puyou A, Logullo C Triosephosphate isomerase (TIM) is an enzyme with a role in glycolysis and gluconeogenesis by catalyzing the interconversion between glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. This enzyme has been used as a target in endoparasite drug development. In this work we cloned, expressed, purified and studied kinetic and structural characteristics of TIM from tick embryos, Rhipicephalus (Boophilus) microplus (BmTIM). The Km and Vmax of the recombinant BmTIM with glyceraldehyde 3-phosphate as substrate, were 0.47mM and 6031μmolmin(-1)mgprotein(-1), respectively. The resolution of the diffracted crystal was estimated to be ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4635279 Tue, 15 Mar 2011 00:00:00 +0100 4635279 http://www.medworm.com/index.php?rid=4635278&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21396446%26dopt%3DAbstract Authors: Yoshido A, Yasukochi Y, Sahara K We performed gene-based comparative FISH mapping between a wild silkmoth, Samia cynthia ssp. with a low number of chromosomes (2n=25-28) and the model species, Bombyx mori (2n=56), in order to identify the genomic components that make up the chromosomes in a low-number karyotype. Mapping of 64 fosmid probes containing orthologs of B. mori genes revealed that the homologues of either two or four B. mori chromosomes constitute the S. c. ricini (Vietnam population, 2n=27♀/28♂, Z0/ZZ) autosomes. Where tested, even the gene order was conserved between S. c. ricini and B. mori. This was also true for the originally autosomal parts of the neo-sex chromosomes in S. c. walkeri (Sapporo population, 2n=26♀/26♂, neo-Wneo-Z/neo-Zneo-Z) and S.Â... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4635278 Mon, 14 Mar 2011 00:00:00 +0100 4635278 http://www.medworm.com/index.php?rid=4572094&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21377527%26dopt%3DAbstract Authors: Rubio RO, Suzukia A, Mitsumasu K, Homma T, Niimi T, Yamashita O, Yaginuma T We previously cloned a cDNA for sorbitol dehydrogenase (SDH1) from Bombyx mori. In the present study we cloned two additional cDNAs encoding SDHs (designated as SDH2a and SDH2b). The amino acid sequences of SDH2ab were almost the same and had higher similarity to the SDHs of other organisms than to B. mori SDH1. The SDH2ab and SDH1genes were located in tandem within about 40 kbp on chromosome 21. SDH2ab mRNAs increased after exposing diapause eggs to 5°C for 40 days, beginning at 2 days post-oviposition, to break diapause. However, they were at very low levels in diapausing eggs incubated at 25°C continuously from oviposition. These changes in expression pattern of SDH2ab mRNA were almost the same as... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4572094 Thu, 03 Mar 2011 00:00:00 +0100 4572094 http://www.medworm.com/index.php?rid=4572093&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21377528%26dopt%3DAbstract Authors: Defferrari MS, Demartini DR, Marcelino TB, Pinto PM, Carlini CR Jackbean (Canavalia ensiformis) ureases are entomotoxic upon the release internal peptides by insect's digestive enzymes. Here we studied the digestive peptidases of Oncopeltus fasciatus (milkweed bug) and its susceptibility to jackbean urease (JBU). O. fasciatus nymphs fed urease showed a mortality rate higher than 80% after two weeks. Homogenates of midguts dissected from fourth instars were used to perform proteolytic activity assays. The homogenates hydrolyzed JBU in vitro, yielding a fragment similar in size to known entomotoxic peptides. The major proteolytic activity at pH 4.0 upon protein substrates was blocked by specific inhibitors of aspartic and cysteine peptidases, but not significantly affected by in... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4572093 Thu, 03 Mar 2011 00:00:00 +0100 4572093 http://www.medworm.com/index.php?rid=4572095&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21376122%26dopt%3DAbstract Authors: Bravo A, Likitvivatanavong S, Gill SS, Soberón M Bacillus thuringiensis (Bt) bacteria are insect pathogens that rely on insecticidal pore forming proteins known as Cry and Cyt toxins to kill their insect larval hosts. At least four different non-structurally related families of proteins form the Cry toxin group of toxins. The expression of certain Cry toxins in transgenic crops has contributed to an efficient control of insect pests resulting in a significant reduction in chemical insecticide use. The mode of action of the three domain Cry toxin family involves sequential interaction of these toxins with several insect midgut proteins facilitating the formation of a pre-pore oligomer structure and subsequent membrane insertion that leads to the killing of midgut insect cells ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4572095 Tue, 01 Mar 2011 00:00:00 +0100 4572095 http://www.medworm.com/index.php?rid=4517683&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21338674%26dopt%3DAbstract Authors: Kiyota R, Arakawa M, Yamakawa R, Yasmin A, Ando T The fall webworm, Hyphantria cunea Drury (Lepidoptera: Arctiidae), is a harmful polyphagous defoliator. Female moths produce the following four pheromone components in a ratio of about 5:4:10:2; (9Z,12Z)-9,12-octadecadienal (I), (9Z,12Z,15Z)-9,12,15-octadecatrienal (II), cis-9,10-epoxy-(3Z,6Z)-3,6-henicosadiene (III), and cis-9,10-epoxy-(3Z,6Z)-1,3,6-henicosatriene (IV). Although (13)C-labeled linolenic acid was not converted into trienal II at the pheromone glands of H. cunea females, GC-MS analysis of an extract of the pheromone gland treated topically with (13)C-labeled linolenyl alcohol showed the aldehyde incorporating the isotope. Other C(18) and C(19) fatty alcohols were also oxidized to the corresponding aldehydes in th... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517683 Fri, 18 Feb 2011 00:00:00 +0100 4517683 http://www.medworm.com/index.php?rid=4517686&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21320598%26dopt%3DAbstract Authors: Oliveira JH, Gonçalves RL, Oliveira GA, Oliveira PL, Oliveira MF, Barillas-Mury C Previous studies showed that Anopheles gambiae L3-5 females, which are refractory (R) to Plasmodium infection, express higher levels of genes involved in redox-metabolism and mitochondrial respiration than susceptible (S) G3 females. Our studies revealed that R females have reduced longevity, faster utilization of lipid reserves, impaired mitochondrial state-3 respiration, increased rate of mitochondrial electron leak and higher expression levels of several glycolytic enzyme genes. Furthermore, when state-3 respiration was reduced in S females by silencing expression of the adenine nucleotide translocator (ANT), hydrogen peroxide generation was higher and the mRNA levels of lactate dehydrogenase... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517686 Sat, 12 Feb 2011 00:00:00 +0100 4517686 http://www.medworm.com/index.php?rid=4517685&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21324358%26dopt%3DAbstract Authors: Ohtsuka K, Atsumi T, Fukushima Y, Shiomi K In the silkworm Bombyx mori and other insects, prothoracicotropic hormone (PTTH) plays a central role in controlling molting and metamorphosis by stimulating the prothoracic glands to synthesize and release the molting hormone ecdysone. Using an AcNPV (Autographa californica nucleopolyhedrovirus)-mediated transient gene transfer system, we identified a cis-regulatory element that participates in the decision to switch expression of PTTH on or off in PTTH-producing neurosecretory cells (PTPCs). The nucleotide sequence of this cis-regulatory element is similar to a cis-regulatory element that participates in direction of expression of diapause hormone-pheromone biosynthesis activating neuropeptide gene (DH-PBAN) (Shiomi et al., 2007). F... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517685 Sat, 12 Feb 2011 00:00:00 +0100 4517685 http://www.medworm.com/index.php?rid=4517684&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21324359%26dopt%3DAbstract Authors: Stevenson BJ, Bibby J, Pignatelli P, Muangnoicharoen S, O'Neill PM, Lian LY, Müller P, Nikou D, Steven A, Hemingway J, Sutcliffe MJ, Paine MJ Resistance to pyrethroid insecticides in the malaria vector Anopheles gambiae is a major threat to malaria control programmes. Cytochome P450-mediated detoxification is an important resistance mechanism. CYP6M2 is over-expressed in wild populations of permethrin resistant A. gambiae but its role in detoxification is not clear. CYP6M2 was expressed in Escherichia coli and a structural model was produced to examine its role in pyrethroid metabolism. Both permethrin and deltamethrin were metabolized. Rates were enhanced by A. gambiae cytochrome b(5) with kinetic parameters of K(M) = 12 ± 4 μM and k(cat) = 6 ± 1 per min for permethrin (1... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517684 Sat, 12 Feb 2011 00:00:00 +0100 4517684 http://www.medworm.com/index.php?rid=4517691&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21296152%26dopt%3DAbstract Authors: Kim JH, Min JS, Kang JS, Kwon DH, Yoon KS, Strycharz J, Koh YH, Pittendrigh BR, Clark JM, Lee SH The differences in the immune response between body lice, Pediculus humanus humanus, and head lice, Pediculus humanus capitis, were investigated initially by measuring the proliferation rates of two model bacteria, a Gram-positive Staphylococcus aureus and a Gram-negative Escherichia coli, following challenge by injection. Body lice showed a significantly reduced immune response compared to head lice particularly to E. coli at the early stage of the immune challenge. Annotation of the body louse genome identified substantially fewer immune-related genes compared with other insects. Nevertheless, all required genetic components of the major immune pathways, except for the immune def... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517691 Fri, 04 Feb 2011 00:00:00 +0100 4517691 http://www.medworm.com/index.php?rid=4517690&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21296153%26dopt%3DAbstract Authors: Boerjan B, Tobback J, De Loof A, Schoofs L, Huybrechts R In Drosophila melanogaster, the male-specific splice isoform of the fruitless gene (Fru(M)) codes for a set of transcription factors that are involved in the regulation of male courtship and copulation. Fru(M) is expressed in an interconnected neuronal circuit containing central and sensory neurons as well as motor neurons. A partial sequence from the Schistocerca gregaria fru-gene from an EST database allowed quantitative real time analysis of fru-expression in adult locusts, and revealed the highest expression in the testes, accessory glands as well as the brain (and optic lobes). Starting fru specific RNAi knockdown in the third and fourth nymphal stage resulted in a significantly lower cumulative copulation frequency... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517690 Fri, 04 Feb 2011 00:00:00 +0100 4517690 http://www.medworm.com/index.php?rid=4517689&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21296154%26dopt%3DAbstract In this study, we found that exons 3-8 of a gene named Bmptp-Z encoding a putative tyrosine-specific protein phosphatase are deleted by the 1.5-Mb interstitial deletion. We found that a gene encoding the Bombyx homolog of Drosophila Apterous (BmAp-A) protein is located 4.5 kb downstream of the distal breakpoint of the 1.5-Mb interstitial deletion. Moreover, an in-frame fusion transcript composed of the 5' part of Bmptp-Z and the 3' part of Bmap-A is generated specific to the Z(Vg) chromosome. Effects of the in-frame fusion transcript on the vestigial phenotype are discussed. PMID: 21296154 [PubMed - as supplied by publisher] (Source: Insect Biochemistry and Molecular Biology) Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517689 Fri, 04 Feb 2011 00:00:00 +0100 4517689 http://www.medworm.com/index.php?rid=4517688&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21296155%26dopt%3DAbstract In this study, we have identified a new member of the β-1,3-glucanase-related protein superfamily from the tobacco hornworm Manduca sexta. This protein, designated microbe binding protein (MBP), is 61% identical in sequence to Bombyx mori Gram-negative bacteria binding protein, but only 34-36% identical to M. sexta β-1,3-glucan recognition protein-1 and 2. Its mRNA levels were strongly up-regulated in hemocytes and fat body of immune challenged larvae, along with an increase in concentration of the plasma protein. We expressed M. sexta MBP in a baculovirus-insect cell system. The purified protein associated with intact bacteria and fungi. It specifically bound to lipoteichoic acid, lipopolysaccharide, diaminopimelic acid-type peptidoglycans (DAP-PGs) from Escherichia coli and Bacillus su... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517688 Fri, 04 Feb 2011 00:00:00 +0100 4517688 http://www.medworm.com/index.php?rid=4517687&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21296156%26dopt%3DAbstract Authors: Watson GB, Loso MR, Babcock JM, Hasler JM, Letherer TJ, Young CD, Zhu Y, Casida JE, Sparks TC The novel sulfoximine insecticide sulfoxaflor is as potent or more effective than the neonicotinoids for toxicity to green peach aphids (GPA, Myzus persicae). The action of sulfoxaflor was characterized at insect nicotinic acetylcholine receptors (nAChRs) using electrophysiological and radioligand binding techniques. When tested for agonist properties on Drosophila melanogaster Dα2 nAChR subunit co-expressed in Xenopus laevis oocytes with the chicken β2 subunit, sulfoxaflor elicited very high amplitude (efficacy) currents. Sulfoximine analogs of sulfoxaflor were also agonists on Dα2/β2 nAChRs, but none produced maximal currents equivalent to sulfoxaflor nor were any as toxic to GP... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517687 Fri, 04 Feb 2011 00:00:00 +0100 4517687 http://www.medworm.com/index.php?rid=4517692&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21295143%26dopt%3DAbstract In this study on the desert locust Schistocerca gregaria, three circadian clock genes were identified and their expression profiles were determined. High expression was predominantly found in reproductive tissues. Similar daily expression profiles were found for period (per) and timeless (tim), while the clock (clk) mRNA level is higher 12h before the first per and tim peak. A knockdown of either per or tim resulted in a significant decrease in the progeny produced by dsRNA treated females confirming the role of clock genes in reproduction and providing evidence that both PER and TIM are needed in the ovaries for egg development. Since the knockdown of clk is lethal for the desert locust, its function remains yet to be elucidated. PMID: 21295143 [PubMed - as supplied by publisher] (So... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517692 Wed, 02 Feb 2011 00:00:00 +0100 4517692 http://www.medworm.com/index.php?rid=4517693&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21288489%26dopt%3DAbstract Authors: Parthasarathy R, Palli SR Female reproduction includes maturation of oocytes and the synthesis of yolk proteins (vitellogenin, Vg) in the fat body and their deposition into the oocytes. Our recent studies showed that juvenile hormone (JH) regulates Vg synthesis and 20-hydroxyecdysone (20E) regulates oocyte maturation in the red flour beetle (Tribolium castaneum). Here, we report on the role of nutritional signaling on vitellogenesis and oogenesis. Comparison of gene expression between fed and starved beetles by microarray analysis showed the up-regulation of genes involved in energy homeostasis and down-regulation of genes involved in egg production in the starved beetles. The RNA interference (RNAi) aided knock-down in the expression of genes involved in insulin and TOR signa... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517693 Tue, 01 Feb 2011 00:00:00 +0100 4517693 http://www.medworm.com/index.php?rid=4517694&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21277979%26dopt%3DAbstract Authors: Yamazaki Y, Kiuchi M, Takeuchi H, Kubo T We previously reported preferential expression of genes for ecdysteroid signaling in the mushroom bodies of honeybee workers, suggesting a role of ecdysteroid signaling in regulating honeybee behaviors. The organs that produce ecdysteroids in worker honeybees, however, remain unknown. We show here that the expression of neverland and Non-molting glossy/shroud, which are involved in early steps of ecdysteroid synthesis, was enhanced in the ovary, while the expression of CYP306A1 and CYP302A1, which are involved in later steps of ecdysone synthesis, was enhanced in the brain, and the expression of CYP314A1, which is involved in converting ecdysone into active 20-hydroxyecdysone (20E), was enhanced in the brain, fat body, and ovary. In in ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517694 Wed, 26 Jan 2011 00:00:00 +0100 4517694 http://www.medworm.com/index.php?rid=4517695&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21255649%26dopt%3DAbstract Authors: Shao Y, Spiteller D, Tang X, Ping L, Colesie C, Münchberg U, Bartram S, Schneider B, Büdel B, Popp J, Heckel DG, Boland W In the animal kingdom, carotenoids are usually absorbed from dietary sources and transported to target tissues. Despite their general importance, the uptake mechanism is still poorly understood. Here we report the "red crop" phenomenon, an accumulation of α- and β-carotene in crystalline inclusions in the enlarged foregut of the polyphagous Spodoptera larvae feeding on some potentially toxic plant leaves. The carotene crystals give the insect foregut a distinctive orange-red color. The crystals are embedded in a homogenous lawn of the bacterium Enterococcus casseliflavus, but the carotene seems to be selectively taken from the food plant. Caterpillars w... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4517695 Wed, 19 Jan 2011 00:00:00 +0100 4517695 http://www.medworm.com/index.php?rid=4393674&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21232599%26dopt%3DAbstract Authors: Gu SH, Wang SP, Zhang XY, Wu KM, Guo YY, Zhou JJ, Zhang YJ Insect odorant binding proteins (OBPs) are required for insect olfaction perception and play a key role in transporting hydrophobic semiochemicals across the sensillum lymph to the olfactory receptors (Ors). We constructed two high-quality cDNA libraries from the male and female antennae of the lucerne plant bug, Adelphocoris lineolatus (Goeze) (Hemiptera: Miridae), a hemipteran species in a large and economically important phylogenetic group of phytophagous insects. A total of 1538 male ESTs and 1576 female ESTs were sequenced and analyzed, which produced 2915 high-quality ESTs for further analysis. The 2915 ESTs were assembled to 1423 unigenes. Of the 1423 unigenes, 895 (63%) showed no significant similarity with any... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4393674 Tue, 11 Jan 2011 00:00:00 +0100 4393674 http://www.medworm.com/index.php?rid=4393676&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21220011%26dopt%3DAbstract Authors: Niu G, Rupasinghe SG, Zangerl AR, Siegel JP, Schuler MA, Berenbaum MR The navel orangeworm Amyelois transitella (Walker) (Lepidoptera: Pyralidae) is a serious pest of many tree crops in California orchards, including almonds, pistachios, walnuts and figs. To understand the molecular mechanisms underlying detoxification of phytochemicals, insecticides and mycotoxins by this species, full-length CYP6AB11 cDNA was isolated from larval midguts using RACE PCR. Phylogenetic analysis of this insect cytochrome P450 monooxygenase established its evolutionary relationship to a P450 that selectively metabolizes imperatorin (a linear furanocoumarin) and myristicin (a natural methylenedioxyphenyl compound) in another lepidopteran species. Metabolic assays conducted with baculovirus-express... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4393676 Sat, 08 Jan 2011 00:00:00 +0100 4393676 http://www.medworm.com/index.php?rid=4393675&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21220012%26dopt%3DAbstract Authors: Lee DW, Shrestha S, Kim AY, Park SJ, Yang CY, Kim Y, Koh YH Sex pheromone production is regulated by pheromone biosynthesis-activating neuropeptide (PBAN) in many lepidopteran species. We cloned a PBAN receptor (Plx-PBANr) gene from the female pheromone gland of the diamondback moth, Plutella xylostella (L.). Plx-PBANr encodes 338 amino acids and has conserved structural motifs implicating in promoting G protein coupling and tyrosine-based sorting signaling along with seven transmembrane domains, indicating a typical G protein-coupled receptor. The expression of Plx-PBANr was found only in the pheromone gland of female adults among examined tissues and developmental stages. Heterologous expression in human uterus cervical cancer cells revealed that Plx-PBANr induced significan... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4393675 Sat, 08 Jan 2011 00:00:00 +0100 4393675 http://www.medworm.com/index.php?rid=4393677&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21216288%26dopt%3DAbstract We describe a circadian rhythm of YP2 accumulation in the UVD seminal fluid, where this protein interacts with sperm in a circadian fashion. However, we also demonstrate that yp2 mRNA and YP2 protein levels within cyst cells show only a diurnal rhythm in light/dark (LD) cycles. These rhythms do not persist in constant darkness (DD), suggesting that they are non-circadian. Interestingly, the per gene and protein levels in cyst cells are rhythmic in LD but not in DD. Nevertheless, per appears to be involved in the diurnal timing of YP2 protein accumulation in cyst cells. PMID: 21216288 [PubMed - as supplied by publisher] (Source: Insect Biochemistry and Molecular Biology) Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4393677 Fri, 07 Jan 2011 00:00:00 +0100 4393677 http://www.medworm.com/index.php?rid=4313723&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21199670%26dopt%3DAbstract Authors: Gu SH, Young SC, Lin JL, Lin PL The prothoracicotropic hormone (PTTH) stimulates ecdysteroidogenesis by prothoracic gland in larval insects. Previous studies showed that Ca(2+), cAMP, extracellular signal-regulated kinase (ERK), and tyrosine kinase are involved in PTTH-stimulated ecdysteroidogenesis by the prothoracic glands of both Bombyx mori and Manduca sexta. In the present study, the involvement of phosphatidylinositol 3-kinase (PI3K)/Akt signaling in PTTH-stimulated ecdysteroidogenesis by B. mori prothoracic glands was further investigated. The results showed that PTTH-stimulated ecdysteroidogenesis was partially blocked by LY294002 and wortmannin, indicating that PI3K is involved in PTTH-stimulated ecdysteroidogenesis. Akt phosphorylation in the prothoracic glands appea... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4313723 Fri, 31 Dec 2010 00:00:00 +0100 4313723 http://www.medworm.com/index.php?rid=4313724&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21195763%26dopt%3DAbstract Juvenile Hormone Synthesis: "esterify then epoxidize" or "epoxidize then esterify"? Insights from the Structural Characterization of Juvenile Hormone Acid Methyltransferase. Insect Biochem Mol Biol. 2010 Dec 30; Authors: Defelipe LA, Dolghih E, Roitberg AE, Nouzova M, Mayoral JG, Noriega FG, Turjanski AG Juvenile hormones (JHs) play key roles in regulating metamorphosis and reproduction in insects. The last two steps of JH synthesis diverge depending on the insect order. In Lepidoptera, epoxidation by a P450 monooxygenase precedes esterification by a juvenile hormone acid methyltransferase (JHAMT). In Orthoptera, Dictyoptera, Coleoptera and Diptera epoxidation follows methylation. The aim of our study was to gain insight into the structural basis of JHAMT's substrate recognitio... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4313724 Thu, 30 Dec 2010 00:00:00 +0100 4313724 http://www.medworm.com/index.php?rid=4313727&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21195177%26dopt%3DAbstract Authors: Lumjuan N, Rajatileka S, Changsom D, Wicheer J, Leelapat P, Prapanthadara LA, Somboon P, Lycett G, Ranson H The Epsilon glutathione transferase (GST) class in the dengue vector Aedes aegypti consists of eight sequentially arranged genes spanning 53,645bp on super contig 1.291, which maps to chromosome 2. One Epsilon GST, GSTE2, has previously been implicated in conferring resistance to DDT. The amino acid sequence of GSTE2 in an insecticide susceptible and a DDT resistant strain differs at five residues two of which occur in the putative DDT binding site. Characterization of the respective recombinant enzymes revealed that both variants have comparable DDT dehydrochlorinase activity although the isoform from the resistant strain has higher affinity for the insecticide. GSTe2 a... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4313727 Wed, 29 Dec 2010 00:00:00 +0100 4313727 http://www.medworm.com/index.php?rid=4313726&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21195178%26dopt%3DAbstract Authors: Marchal E, Zhang J, Badisco L, Verlinden H, Hult EF, Van Wielendaele P, Yagi KJ, Tobe SS, Broeck JV Two genes coding for enzymes previously reported to be involved in the final steps of juvenile hormone (JH) biosynthesis in different insect species, were characterised in the desert locust, Schistocerca gregaria. Juvenile hormone acid O-methyltransferase (JHAMT) was previously described to catalyse the conversion of farnesoic acid (FA) and JH acid to their methyl esters methyl farnesoate (MF) and JH respectively. A second gene, CYP15A1 was reported to encode a cytochrome P450 enzyme responsible for the epoxidation of MF to JH. Additionally, a third gene, FAMeT (originally reported to encode a farnesoic acid methyltransferase) was included in this study. Using q-RT-PCR, all thre... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4313726 Wed, 29 Dec 2010 00:00:00 +0100 4313726 http://www.medworm.com/index.php?rid=4313725&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21195179%26dopt%3DAbstract Authors: Zhang D, Lax AR, Bland JM, Allen AB The present work characterized a new endogenous cellulase (endo-β-1,4-glucanase) gene, CfEG5, uncovered in the transcriptome of Formosan subterranean termite (Coptotermes formosanus). The full-length gene was cloned and sequenced. It is similar to the CfEG3a described earlier (Zhang et al. 2009) but not likely an allelic variant. GenomeWalkerâ„¢ DNA walking analysis indicated that there may be one copy of CfEG5 and two copies of CfEG3a in the termite genome. As with CfEG3a, the transcript of CfEG5 was detected predominantly in the salivary gland based on quantitative RT-PCR. Phylogenetic analysis of translated amino acid sequence showed that the CfEG5 is more related to CaEG, derived from an Australian subterranean termite (C. acinaciformis... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4313725 Wed, 29 Dec 2010 00:00:00 +0100 4313725 http://www.medworm.com/index.php?rid=4313728&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21167282%26dopt%3DAbstract Authors: Futahashi R, Tanaka K, Matsuura Y, Tanahashi M, Kikuchi Y, Fukatsu T During the maturation of insect cuticle, protein-protein and protein-chitin crosslinkages are formed by the action of diphenoloxidases. Two types of diphenoloxidases, laccases and tyrosinases, are present in the insect cuticle. In coleopteran and hymenopteran insects, laccase2 gene has been identified as encoding an enzyme principally responsible for cuticular pigmentation and hardening, whereas biological roles of laccase genes in hemimetabolous insects remain to be established. Here we identified laccase2 genes from three hemipteran stinkbugs, Riptortus pedestris (Alydidae), Nysius plebeius (Lygaeidae) and Megacopta punctatissima (Plataspidae). In R. pedestris, laccase2 gene was highly expressed in epiderm... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4313728 Wed, 15 Dec 2010 00:00:00 +0100 4313728 http://www.medworm.com/index.php?rid=4270754&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21146607%26dopt%3DAbstract Authors: Dechklar M, Tiewsiri K, Angsuthanasombat C, Pootanakit K Bacillus thuringiensis produces insecticidal crystal (Cry) proteins which bind to cell surface receptors on the brush border membrane of susceptible midgut larvae. The toxin-receptor interaction generates pores in midgut epithelial cells resulting in cell lysis. Here, a cDNA encoding membrane-bound alkaline phosphatase from Aedes aegypti (Aa-mALP) midgut larvae, based on the sequence identity hit to Bombyx mori membrane-bound ALP, was amplified by RT-PCR and transiently expressed in Spodoptera frugiperda (Sf9) insect cells as a 58-kDa membrane-bound protein via the baculovirus expression system and confirmed by digestion with phosphatidylinositol-specific phospholipase C and LC-MS/MS analysis. Immunolocalization results ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4270754 Thu, 09 Dec 2010 00:00:00 +0100 4270754 http://www.medworm.com/index.php?rid=4270753&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21146608%26dopt%3DAbstract In this study, we employed heritable RNA interference (RNAi) in combination with the GAL4/UAS system to spatiotemporally knockdown the dRNaseZ gene and study its biological role in cells of a developing fruit fly. We found that dRNaseZ is an essential gene, as ubiquitous knockdown caused growth arrest and early larval lethality. Molecular analysis confirmed that dRNaseZ is necessary for 3'-end processing of nuclear and mitochondrial tRNAs: knockdown larvae displayed significant accumulation of both types of processing intermediates with extensions at the 3' end. This is the first in vivo demonstration of RNase Z(L) dependent tRNA processing in the context of a metazoan model organism. Using tissue-specific GAL4 drivers, we also showed that in mitotically growing imaginal discs dRNaseZ is r... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4270753 Thu, 09 Dec 2010 00:00:00 +0100 4270753 http://www.medworm.com/index.php?rid=4270752&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21146609%26dopt%3DAbstract Authors: Mathew LG, Campbell EM, Yool AJ, Fabrick JA Some hemipteran xylem and phloem feeding insects have evolved specialized alimentary structures or filter chambers that rapidly transport water for excretion or osmoregulation. In the whitefly, Bemisia tabaci, mass movement of water through opposing alimentary tract tissues within the filter chamber is likely facilitated by an aquaporin protein. B. tabaci aquaporin-1 (BtAQP1) possesses characteristic aquaporin topology and conserved pore-forming residues found in water-specific aquaporins. As predicted for an integral transmembrane protein, recombinant BtAQP1 expressed in cultured insect cells localized within the plasma membrane. BtAQP1 is primarily expressed in early instar nymphs and adults, where in adults it is localized in the ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4270752 Thu, 09 Dec 2010 00:00:00 +0100 4270752 http://www.medworm.com/index.php?rid=4214905&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21112395%26dopt%3DAbstract Authors: Kakani EG, Bon S, Massoulié J, Mathiopoulos KD The olive fly Bactrocera oleae is the most destructive and intractable pest of olives. The management of B. oleae has been based on the use of organophosphate (OP) insecticides, a practice that induced resistance. OP-resistance in the olive fly was previously shown to be associated with two mutations in the acetylcholinesterase (AChE) enzyme that, apparently, hinder the entrance of the OP into the active site. The search for additional mutations in the ace gene that encodes AChE revealed a short deletion of three glutamines (Δ3Q) from a stretch of five glutamines, in the C-terminal peptide that is normally cleaved and substituted by a GPI anchor. We verified that AChEs from B. oleae and other Dipterans are actually GPI-anchored,... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4214905 Thu, 25 Nov 2010 00:00:00 +0100 4214905 http://www.medworm.com/index.php?rid=4214906&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21111817%26dopt%3DAbstract Authors: Minakuchi C, Tanaka M, Miura K, Tanaka T In holometabolous insects, Krüppel homolog 1 (Kr-h1) and broad (br) are key players in the juvenile hormone (JH) regulation of metamorphosis: Kr-h1 is an early JH-response gene, while br is a transcription factor that directs pupal development. Thrips (Thysanoptera) are classified as hemimetabolous insects that develop directly from nymph to adult, but they have quiescent and non-feeding stages called propupa and pupa. We analyzed the developmental profiles of br and Kr-h1 in the western flower thrips Frankliniella occidentalis (Thripidae) that has one propupal instar and one pupal instar, and Haplothrips brevitubus (Phlaeothripidae) that has one propupal instar and two pupal instars, i.e. pupa I and pupa II. In F. occidentalis, the br... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4214906 Wed, 24 Nov 2010 00:00:00 +0100 4214906 http://www.medworm.com/index.php?rid=4182563&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21078388%26dopt%3DAbstract Authors: Royer C, Briolay J, Garel A, Brouilly P, Sasanuma SI, Sasanuma M, Shimomura M, Keime C, Gandrillon O, Huang Y, Chavancy G, Mita K, Couble P Serial analysis of gene expression (SAGE) profiles, from posterior and median cells of the silk gland of Bombyx mori, were analyzed and compared, so as to identify their respective distinguishing functions. The annotation of the SAGE libraries was performed with a B. mori reference tag collection, which was extracted from a novel set of Bombyx ESTs, sequenced from the 3' side. Most of the tags appeared at similar relative concentration within the two libraries, and corresponded with region-specific and highly abundant silk proteins. Strikingly, in addition to tags from silk protein mRNAs, 19 abundant tags were found (≥0.1%), in the media... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4182563 Fri, 12 Nov 2010 00:00:00 +0100 4182563 http://www.medworm.com/index.php?rid=4182562&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21078389%26dopt%3DAbstract Authors: Irles P, Piulachs MD Molecular aspects of chorion synthesis in insects have been studied deeply in species with meroistic ovaries. Information available in insects with panoistic ovaries is principally structural whereas molecular information in these species is scarce. This paper seeks to balance the above situation by describing a novel chorion gene, Citrus, from the cockroach Blattella germanica, a phylogenetically basal hemimetabolan insect with reproduction regulated by juvenile hormone and with panoistic ovaries. During previous work we discovered a series of novel genes which were specifically expressed during chorion formation in B. germanica. One of them, herein named Citrus, was peculiar due to its high copy number and its very transient expression. In the present pa... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4182562 Fri, 12 Nov 2010 00:00:00 +0100 4182562 http://www.medworm.com/index.php?rid=4182561&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21078390%26dopt%3DAbstract Authors: Kristiansen E, Ramløv H, Højrup P, Pedersen SA, Hagen L, Zachariassen KE Antifreeze proteins (AFPs) are characterized by their capacity to inhibit the growth of ice and are produced by a variety of polar fish, terrestrial arthropods and other organisms inhabiting cold environments. This capacity reflects their role as stabilizers of supercooled body fluids. The longhorn beetle Rhagium inquisitor is known to express AFPs in its body fluids. In this work we report on the primary structure and structural characteristics of a 12.8 kDa AFP from this beetle (RiAFP). It has a high capacity to evoke antifreeze activity as compared to other known insect AFPs and it is structurally unique in several aspects. In contrast to the high content of disulfide bond-formation observed in other... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4182561 Fri, 12 Nov 2010 00:00:00 +0100 4182561 http://www.medworm.com/index.php?rid=4164352&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21056664%26dopt%3DAbstract Authors: Allen JE, Wanner KW Most moth species in the genus Ostrinia use varying ratios of Z11- and E11-tetradecenyl acetate as their main sex pheromone components. The Asian corn borer is unique within the genus having evolved to use pheromone components with a shift in the location of the double bond, Z12- and E12-tetradecenyl acetate. We identified cDNAs representing five pheromone binding proteins (PBPs) and two sensory neuron membrane protein genes from an antennal transcriptome. The coding regions of the orthologous genes were cloned from the Asian corn borer and the E and Z sex pheromone races of the European corn borer. Their nucleotide sequences and transcript expression levels were analyzed to identify candidate genes from the Asian corn borer that may have evolved specificit... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4164352 Thu, 04 Nov 2010 00:00:00 +0100 4164352 http://www.medworm.com/index.php?rid=4164351&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21056665%26dopt%3DAbstract Authors: Lu HL, Kersch C, Pietrantonio PV It is known that insect kinins increase diuresis and fluid secretion in the Aedes aegypti Malpighian tubule, causing a rapid drop of the transepithelial resistance and increasing chloride conductance from the hemolymph towards the tubule lumen. The tubule is composed of both principal and stellate cells. The main route for increased chloride influx upon kinin treatment is proposed to be paracellular, with septate junctions acquiring increased chloride selectivity and conductance. Therefore, kinin treatment renders the Aedes aegypti tubule a "leaky epithelium", and under this model the kinin receptor is postulated to be expressed in principal cells. However, in another dipteran, the fruit fly Drosophila melanogaster, the main route for chloride ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4164351 Thu, 04 Nov 2010 00:00:00 +0100 4164351 http://www.medworm.com/index.php?rid=4135142&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21044684%26dopt%3DAbstract Authors: Intra J, De Caro D, Perotti ME, Pasini ME Fruit flies in the family Tephritidae are rated among the world's most destructive agricultural pests. The Mediterranean fruit fly Ceratitis capitata is emerging as a model organism to study the fertilization in insects. Three integral proteins with glycosidase activity are present in the plasma membrane of spermatozoa. The glycosidases have been purified and characterized. We have demonstrated the presence of three enzymes, a β-N-acetylhexosaminidase, an α-mannosidase and an α-L-fucosidase. The molecular mass of the native enzymes estimated by gel filtration was 160 kDa for β-N-acetylhexosaminidase, 310 kDa for α-mannosidase and 140 kDa for α-L-fucosidase. SDS-PAGE showed that β-N-acetylhexosaminidase is a dimer of a single pro... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4135142 Sat, 30 Oct 2010 00:00:00 +0100 4135142 http://www.medworm.com/index.php?rid=4135144&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21035548%26dopt%3DAbstract Authors: Tohidi-Esfahani D, Graham LD, Hannan GN, Simpson AM, Hill RJ It has been suggested that Pentatomomorpha utilise the C(28) ecdysteroid, makisterone A (MakA), as the major moulting hormone rather than the more common C(27) hormone, 20-hydroxyecdsyone (20E). The present study is the first to examine this postulate at the level of the ecdysone receptor protein, a heterodimer of nuclear receptors EcR and USP. cDNAs encoding two alternatively spliced isoforms of EcR and a single USP were isolated from a high-quality cDNA library prepared from a representative pentatomomorphan, Nezara viridula (Nv). NvEcR and NvUSP were found to group phylogenetically with heteropteran and other insect EcRs and USP/RXRs, respectively. Sequence comparison and phylogenetic analysis of these proteins fo... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4135144 Wed, 27 Oct 2010 00:00:00 +0100 4135144 http://www.medworm.com/index.php?rid=4135143&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21035549%26dopt%3DAbstract This study represents a notable step in deciphering molecular pathways controlling reproduction of this important vector of human diseases. PMID: 21035549 [PubMed - as supplied by publisher] (Source: Insect Biochemistry and Molecular Biology) Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4135143 Wed, 27 Oct 2010 00:00:00 +0100 4135143 http://www.medworm.com/index.php?rid=4061158&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20933086%26dopt%3DAbstract In this study we report the full length cDNA cloning of the three Ctenocephalides (C.) felis (cat flea) nAChR α subunits Cfα1, Cfα2, and Cfα3. When expressed in Xenopus oocytes as hybrid receptors with the Gallus gallus (chicken) β2 (Ggβ2) subunit, these cat flea α subunits formed acetylcholine-responsive ion channels. Acetylcholine-evoked currents of Cfα2/Ggβ2 were resistant to α-bungarotoxin, while those of Cfα1/Ggβ2 were sensitive to this snake toxin. The pharmacological profiles of Cfα1/Ggβ2, Cfα2/Ggβ2 and the chicken neuronal receptor Ggα4/Ggβ2 for acetylcholine, two nicotinoids and 6 insecticidal neonicotinoids were determined and compared. Particularly remarkable was the finding that Cfα1/Ggβ2 was far more sensitive to acetylcholine, nicotine and neonicotinoid ag... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4061158 Mon, 04 Oct 2010 23:00:00 +0100 4061158 http://www.medworm.com/index.php?rid=4040837&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20920581%26dopt%3DAbstract Authors: Arakane Y, Baguinon MC, Jasrapuria S, Chaudhari S, Doyungan A, Kramer KJ, Muthukrishnan S, Beeman RW A bioinformatics search of the genome of the red flour beetle, Tribolium castaneum, resulted in the identification of two genes encoding proteins closely related to UDP-N-acetylglucosamine pyrophosphorylases (UAPs), which provide the activated precursor, UDP-N-acetylglucosamine, for the synthesis of chitin, glycoproteins and glycosylphosphoinositide (GPI) anchors of some membrane proteins as well as for the modification of other substrates. This is in contrast to other arthropods whose genomes have been completely sequenced, all of which have only a single copy of this gene. The two T. castaneum UAP genes, TcUAP1 and TcUAP2, share both nucleotide and amino acid sequence identit... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4040837 Thu, 30 Sep 2010 23:00:00 +0100 4040837 http://www.medworm.com/index.php?rid=4040838&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20888910%26dopt%3DAbstract Authors: Cui F, Lin Z, Wang H, Liu S, Chang H, Reeck G, Qiao C, Raymond M, Kang L Carboxylesterases provide key mechanisms of resistance to insecticides, particularly organophosphates (OPs), in insects. One resistance mechanism is a qualitative change in the properties of a carboxylesterase. Two mutant forms, G151D and W271L, have been observed, mostly in dipteran species, to affect substrate specificity of enzymes. But whether these two single mutations can commonly change character of insect carboxylesterases is unknown. In our study carboxylesterase genes from seven insects distributed among four orders were cloned, mutated at position 151 or 271 and expressed in Escherichia coli. The kinetics of the purified recombinant proteins was examined towards an artificial carboxyl-ester and... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4040838 Wed, 29 Sep 2010 23:00:00 +0100 4040838 http://www.medworm.com/index.php?rid=4040839&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20888415%26dopt%3DAbstract In this study, we examined the effects of lidocaine on a cockroach sodium channel variant, BgNa(v)1-1a, and determined whether F1817 and Y1824 are also critical for the action of LAs on insect sodium channels. Lidocaine blocked BgNa(v)1-1a channels in the resting state with potency similar to that observed in mammalian sodium channels. Lidocaine also stabilized both fast-inactivated and slow-inactivated states of BgNa(v)1-1a channels, and caused a limited degree of use- and frequency-dependent block, major characteristics of LA action on mammalian sodium channels. Alanine substitutions of F1817 and Y1824 reduced the sensitivity of the BgNa(v)1-1a channel to the use-dependent block by lidocaine, but not to tonic blocking and inactivation stabilizing effects of lidocaine. Thus, similar to th... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4040839 Tue, 28 Sep 2010 23:00:00 +0100 4040839 http://www.medworm.com/index.php?rid=4040840&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20887788%26dopt%3DAbstract Authors: Alout H, Labbé P, Pasteur N, Weill M The status of genes conferring resistance to organophosphate and carbamate insecticides has been examined in Culex pipiens pipiens mosquitoes sampled in Algeria. Presence of overproduced esterases was sporadic, but acetylcholinesterase-1 resistant alleles were observed in almost all samples. We focused our study on the AChE1 G119S substitution characterized in almost all samples, mostly at the heterozygous state. A genetic test revealed the presence of ace-1 duplication associating a susceptible and a resistant ace-1 copy. Molecular characterization showed a high occurrence of ace-1 duplication with six distinct duplicated alleles out of four samples. The inferred frequency of duplicated allele suggests that it is replacing the single resi... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4040840 Mon, 27 Sep 2010 23:00:00 +0100 4040840 http://www.medworm.com/index.php?rid=4025478&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20875854%26dopt%3DAbstract Authors: Qian S, Fujii T, Ito K, Nakano R, Ishikawa Y Sex pheromones of moths are largely classified into two types based on the presence (Type I) or absence (Type II) of a terminal functional group. While Type-I sex pheromones are synthesized from common fatty acids in the pheromone gland (PG), type-II sex pheromones are derived from hydrocarbons produced presumably in the oenocytes and transported to the PG via the hemolymph. Recently, a fatty acid transport protein (BmFATP) was identified from the PG of the silkworm Bombyx mori, which produces a type-I sex pheromone (bombykol). BmFATP was shown to facilitate the uptake of extracellular fatty acids into PG cells for the synthesis of bombykol. To elucidate the presence and function of FATP in the PG of moths that produce Type-II sex p... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4025478 Fri, 24 Sep 2010 23:00:00 +0100 4025478 http://www.medworm.com/index.php?rid=4025477&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20875855%26dopt%3DAbstract Authors: Wu S, Yang Y, Yuan G, Campbell PM, Teese MG, Russell RJ, Oakeshott JG, Wu Y Enhanced detoxification is the major mechanism responsible for pyrethroid resistance in Chinese populations of Helicoverpa armigera. Previous work has shown that enhanced oxidation contributes to resistance in the fenvalerate-selected Chinese strain, YGF. The current study provides evidence that enhanced hydrolysis by esterase isozymes also contributes to the resistance in this strain. The average esterase activity of third instar YGF larvae was 1.9-fold compared with that of a susceptible SCD strain. Much of this difference was attributed to isozymes at two zones which hydrolysed the model carboxylester substrate 1-naphthyl acetate and also a 1-naphthyl analogue of fenvalerate.A preparation enriched f... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4025477 Fri, 24 Sep 2010 23:00:00 +0100 4025477 http://www.medworm.com/index.php?rid=4025480&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20869440%26dopt%3DAbstract Authors: Concha C, Belikoff EJ, Carey BL, Li F, Schiemann AH, Scott MJ The green blowfly species L. cuprina and L. sericata are economically important pests for the sheep industries of Australia and New Zealand. L. cuprina has long been considered a good target for a genetic pest management program. In addition, L. sericata maggots are used in the cleaning of wounds and necrotic tissue of patients suffering from ulcers that are difficult to treat by other methods. Development of efficient transgenesis methods would greatly facilitate the development of strains ideal for genetic control programs or could potentially improve "maggot therapy". We have previously reported the germ-line transformation of Lucilia cuprina and the design of a "female killing system" that could potentially be a... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4025480 Tue, 21 Sep 2010 23:00:00 +0100 4025480 http://www.medworm.com/index.php?rid=4025479&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20869441%26dopt%3DAbstract In this study, we changed this F to C in a pyrethroid-sensitive cockroach sodium channel and examined mutant channel sensitivity to permethrin as well as five other type I or type II pyrethroids in Xenopus oocytes. Interestingly, the F to C mutation drastically reduced channel sensitivity to three type I pyrethroids, permethrin, NRDC 157 (a deltamethrin analogue lacking the α-cyano group) and bioresemthrin, but not to three type II pyrethroids, cypermethrin, deltamethrin and cyhalothrin. These results confirm the involvement of the F to C mutation in permethrin resistance, and raise the possibility that rotation of type I and type II pyrethroids might be considered in the control of insect pest populations where this particular mutation is present. PMID: 20869441 [PubMed - as suppli... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4025479 Tue, 21 Sep 2010 23:00:00 +0100 4025479 http://www.medworm.com/index.php?rid=4025481&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20854909%26dopt%3DAbstract Authors: Zhang C, Luo X, Ni X, Zhang Y, Li X How plant allelochemicals elicit herbivore counterdefense genes remains largely unknown. To define the cis-acting elements for flavone inducibility of the allelochemical-metabolizing CYP321A1 from Helicoverpa zea, functions of varying length of CYP321A1 promoter are examined in H. zea fatbody cells. Progressive 3' deletions reveal presence of positive elements in the 5' untranslated region (UTR). Progressive 5' deletions map out regions of one essential element, four enhancers, and two silencers. Further progressive 5'deletions localize the essential element to a 36-bp region from -109 to -74. This essential element, designated as xenobiotic response element to flavone (XRE-Fla), contains a 5' AT-only TAAT inverted repeat, a GCT mirror repea... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=4025481 Fri, 17 Sep 2010 23:00:00 +0100 4025481 http://www.medworm.com/index.php?rid=3987808&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20849954%26dopt%3DAbstract Authors: Gruntenko NE, Wen D, Karpova EK, Adonyeva NV, Liu Y, He Q, Faddeeva NV, Fomin AS, Li S, Rauschenbach IY Juvenile hormone (JH), which controls many developmental and physiological processes in Drosophila melanogaster, is synthesized de novo in the specialized endocrine glands, corpus allatum (CA). The present study concerns JH metabolism, reproduction and stress resistance in Drosophila with genetic ablation of a part of CA cells. The correlated regulation of JH biosynthesis and degradation in Drosophila adults has been found: ablation of CA cells led to (1) a dramatic decrease in activity of the key regulatory enzyme of JH biosynthesis, juvenile hormone acid methyl transferase and (2) a considerable increase in JH-hydrolyzing activity. It has been also shown that ablation of C... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3987808 Mon, 13 Sep 2010 23:00:00 +0100 3987808 http://www.medworm.com/index.php?rid=3987807&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20851767%26dopt%3DAbstract Authors: Caiaffa CD, Stiebler R, Oliveira MF, Lara FA, Paiva-Silva GO, Oliveira PL Hematophagy is a feeding habit that involves the ingestion of huge amounts of heme. The hematophagous hemipteran Rhodnius prolixus evolved many genetic resources to protect cells against heme toxicity. The primary barrier against the deleterious effects of heme is the aggregation of heme into hemozoin in the midgut lumen. Hemozoin formation is followed by the enzymatic degradation of heme by means of a unique pathway whose end product is dicysteinyl-biliverdin IX-γ (Rhodnius prolixus biliverdin, RpBv). These mechanisms are complemented by a heme-binding protein (RHBP) in the hemolymph that attenuates the pro-oxidant effects of heme. In this work, we show that when insects are fed with blood enriched w... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3987807 Sun, 12 Sep 2010 23:00:00 +0100 3987807 http://www.medworm.com/index.php?rid=3961600&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20826210%26dopt%3DAbstract Authors: Lee JH, Kim CH, Shin YP, Park HJ, Park S, Lee HM, Kim BS, Lee IH We characterized a Kunitz-type protease inhibitor (Gm KTPI) obtained from the hemolymph of Galleria mellonella larvae immunized with E. coli. The structural analysis of the cloned cDNA showed that it consists of 56 residues derived from the precursor of 75 amino acids. The peptide was constitutively produced in the fat bodies, but not in the midgut nor the integument of larvae. In our analysis of stage-dependent expression, its transcript was detected within the midgut, the fat bodies and the integument of the prepupae, which undergo tissue remodeling. The inhibition assays showed that Gm KTPI was capable of inhibiting only the trypsin-like activity of the larval midgut extracts. Furthermore, it was determined th... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3961600 Thu, 02 Sep 2010 23:00:00 +0100 3961600 http://www.medworm.com/index.php?rid=3961599&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20826211%26dopt%3DAbstract Authors: Hamshou M, Smagghe G, Shahidi-Noghabi S, De Geyter E, Lannoo N, Van Damme EJ This project studied in detail the insecticidal activity of a fungal lectin from the sclerotes of Sclerotinia sclerotiorum, referred to as Sclerotinia sclerotiorum agglutinin or SSA. Feeding assays with the pea aphid (Acyrthosiphon pisum) on an artificial diet containing different concentrations of SSA demonstrated a high mortality caused by this fungal lectin with a median insect toxicity value (LC(50)) of 66 (49-88) μg/ml. In an attempt to unravel the mode of action of SSA the binding and interaction of the lectin with insect tissues and cells were investigated. Histofluorescence studies on sections from aphids fed on an artificial liquid diet containing FITC-labeled SSA, indicated the insect mid... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3961599 Thu, 02 Sep 2010 23:00:00 +0100 3961599 http://www.medworm.com/index.php?rid=3961601&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20816775%26dopt%3DAbstract Authors: Bragatto I, Genta FA, Ribeiro AF, Terra WR, Ferreira C Spodoptera frugiperda beta-1,3-glucanase (SLam) was purified from larval midgut. It has a molecular mass of 37.5 kDa, an alkaline optimum pH of 9.0, is active against beta-1,3-glucan (laminarin), but can not hydrolyse yeast beta-1,3-1,6-glucan or other polysaccharides. The enzyme is an endo-glucanase with low processivity (0.4), and is not inhibited by high concentrations of substrate. In contrast to other digestive beta-1,3-glucanases from insects, SLam is unable to lyse Saccharomyces cerevisae cells. The cDNA encoding SLam was cloned and sequenced, showing that the protein belongs to glycosyl hydrolase family 16 as other insect glucanases and glucan-binding proteins. Multiple sequence alignment of beta-1,3-glucanases and... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3961601 Mon, 30 Aug 2010 23:00:00 +0100 3961601 http://www.medworm.com/index.php?rid=3911487&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20728536%26dopt%3DAbstract Authors: Sugimoto TN, Fujii T, Kayukawa T, Sakamoto H, Ishikawa Y A homologue of the sex-determining gene doublesex, Osdsx, was identified in the adzuki bean borer Ostrinia scapulalis. Three isoforms of the Osdsx transcript (Osdsx(M), Osdsx(FL) and Osdsx(FS)) differing in length were found. Osdsx(M) was specifically found in males, and contained an 852-bp ORF encoding a protein of 284 amino acids. Osdsx(FL) and Osdsx(FS) were found in females, and had the same 813-bp ORF encoding a protein of 271 amino acids. The Osdsx gene was inferred to have six exons and five introns. The variation in the transcript could be explained by the alternative splicing of Osdsx: Osdsx(M) was formed by the splicing of exons 1, 2, 5 and 6, Osdsx(FS) by the splicing of exons 1-4 and 6, and Osdsx(FL) by the s... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3911487 Wed, 18 Aug 2010 23:00:00 +0100 3911487 http://www.medworm.com/index.php?rid=3911486&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20728537%26dopt%3DAbstract Authors: Ribeiro JM, Mans BJ, Arcà B Within the Diptera and outside the suborder Brachycera, the blood feeding habit occurred at least twice, producing the present day sand flies, and the Culicomorpha, including the mosquitoes (Culicidae), black flies (Simulidae), biting midges (Ceratopogonidae) and frog feeding flies (Corethrellidae). Alternatives to this scenario are also discussed. Successful blood feeding requires adaptations to antagonize the vertebrate's mechanisms of blood clotting, platelet aggregation, vasoconstriction, pain and itching, which are triggered by tissue destruction and immune reactions to insect products. Saliva of these insects provides a complex pharmacological armamentarium to block these vertebrate reactions. With the advent of transcriptomics, the sialome... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3911486 Wed, 18 Aug 2010 23:00:00 +0100 3911486 http://www.medworm.com/index.php?rid=3911489&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20727969%26dopt%3DAbstract Authors: Rand MD, Kearney AL, Dao J, Clason T Pharmacological manipulations in the Drosophila embryo have been hindered by the impermeability of the eggshell. The ultimate barrier to delivery of small molecule solutes to the embryo is the waxy layer that lies beneath the external chorion layers and encases the underlying vitelline membrane of the eggshell.Conventional protocols call forheptane or octane to permeablize the dechorionated eggshell however, these solvents are toxic and can result in low viability. Furthermore, heptane and octane require transition of the embryo between aqueous and organic phase solvents making it challenging to avoid desiccation. Here we describe an embryo permeabilization solvent (EPS) composed of D-limonene and plant-derived surfactantsthat is water misc... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3911489 Tue, 17 Aug 2010 23:00:00 +0100 3911489 http://www.medworm.com/index.php?rid=3911488&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20727970%26dopt%3DAbstract Authors: Blomquist GJ, Teran RF, Aw M, Song M, Gorzalski A, Abbot N, Chang E, Tittiger C The first aggregation pheromone components from bark beetles were identified in 1966 as a mixture of ipdienol, ipsenol and verbenol. Since then, a number of additional components have been identified as both aggregation and anti-aggregation pheromones, with many of them being monoterpenoids or derived from monoterpenoids. The structural similarity between the major pheromone components of bark beetles and the monoterpenes found in the host trees, along with the association of monoterpenoid production with plant tissue, led to the paradigm that most if not all bark beetle pheromone components were derived from host tree precursors, often with a simple hydroxylation producing the pheromone. In the 19... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3911488 Tue, 17 Aug 2010 23:00:00 +0100 3911488 http://www.medworm.com/index.php?rid=3911490&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20727410%26dopt%3DAbstract Authors: Miyaji T, Murayama S, Kouzuma Y, Kimura N, Kanost MR, Kramer KJ, Yonekura M A Manduca sexta (tobacco hornworm) cysteine protease inhibitor, MsCPI, purified from larval hemolymph has an apparent molecular mass of 11.5kDa, whereas the size of the mRNA is very large ( 9 kilobases). MsCPI cDNA consists of a 9,273 nucleotides that encode a polypeptide of 2,676 amino acids, which includes nine tandemly repeated MsCPI domains, four cystatin-like domains and one procathepsin F-like domain. The procathepsin F-like domain protein was expressed in Escherichia coli and processed to its active mature form by incubation with pepsin. The mature enzyme hydrolyzed Z-Leu-Arg-MCA, Z-Phe-Arg-MCA and Boc-Val-Leu-Lys-MCA rapidly, whereas hydrolysis of Suc-Leu-Tyr-MCA and Z-Arg-Arg-MCA was very slow... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3911490 Mon, 16 Aug 2010 23:00:00 +0100 3911490 http://www.medworm.com/index.php?rid=3881987&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20713155%26dopt%3DAbstract Authors: Zhang J, Liu X, Zhang J, Li D, Guo Y, Ma E, Zhu KY Chitin synthases are crucial enzymes responsible for chitin biosynthesis in fungi, nematodes and arthropods. We characterized two alternative splicing-derived variants of chitin synthase 1 gene (LmCHS1) from the oriental migratory locust, Locusta migratoria manilensis (Meyen). Each cDNA of the two variants (LmCHS1A and LmCHS1B) consists of 5,116 nucleotides that include a 4,728-nucleotide open reading frame (ORF) encoding 1,576 amino acid residues, and 67- and 321-bp non-coding regions at the 5'- and 3'-ends of the cDNA, respectively. The two variants differ only in one exon consisting of 177 nucleotides that encode 59 amino acid residues. The amino acid sequences within this alternative splicing region are 75% identical betwe... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3881987 Thu, 12 Aug 2010 23:00:00 +0100 3881987 http://www.medworm.com/index.php?rid=3881988&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20709171%26dopt%3DAbstract Authors: Edwards MG, Gatehouse JA, Gatehouse AM The ability of phytophagous insects to utilise the relatively low nitrogen content of plant tissues is typically the limiting factor in their nutritional uptake. In the larval stage, the vine weevil feeds predominantly on root tissues of plants. The root tissue as a whole has low levels of free amino acids, and thus effective hydrolysis of dietary proteins is essential for survival. In contrast to previous reports the present study demonstrates through both molecular and biochemical studies the presence of proteolytic enzymes from two mechanistic classes, cysteine and serine proteases, in the gut of larval vine weevil; with the latter being the predominant form. cDNA clones encoding cathepsin B-like and serine-like sequences were isolated... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3881988 Wed, 11 Aug 2010 23:00:00 +0100 3881988 http://www.medworm.com/index.php?rid=3869364&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20705134%26dopt%3DAbstract Authors: Meyer H, Von Ohlen T, Panz M, Paululat A A Disintegrin And Metalloprotease (ADAM) proteins belong to the metzincin superfamily of metalloproteases that are known to play important roles in several physiological and developmental processes including myoblast fusion, tumor necrosis factor-alpha release or fertilization. They are characterized by a typical domain structure with a proteolytically active domain and the protein binding domains both facing the extracellular space. Regulatory mechanisms are largely unknown. Here we report on the potential of the Drosophila ADAM Meltrin to form oligomers via its substrate binding domain. Significantly, oligomerization occurs apparently in a redox dependent manner. Further analysis revealed that the ACR domain is responsible for aggrega... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3869364 Sun, 08 Aug 2010 23:00:00 +0100 3869364 http://www.medworm.com/index.php?rid=3869363&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20705135%26dopt%3DAbstract Authors: Kikuta S, Kikawada T, Hagiwara-Komoda Y, Nakashima N, Noda H The brown planthopper (BPH), Nilaparvata lugens, attacks rice plants and feeds on their phloem sap, which contains large amounts of sugars. The main sugar component of phloem sap is sucrose, a disaccharide composed of glucose and fructose. Sugars appear to be incorporated into the planthopper body by sugar transporters in the midgut. A total of 93 expressed sequence tags (ESTs) for putative sugar transporters were obtained from a BPH EST database, and 18 putative sugar transporter genes (Nlst1-18) were identified. The most abundantly expressed of these genes was Nlst1. This gene has previously been identified in the BPH as the glucose transporter gene NlHT1, which belongs to the major facilitator superfamily. Nlst1, ... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3869363 Sun, 08 Aug 2010 23:00:00 +0100 3869363 http://www.medworm.com/index.php?rid=3869368&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20691784%26dopt%3DAbstract Authors: Coy MR, Salem TZ, Denton JS, Kovaleva E, Liu Z, Barber DS, Campbell JH, Davis DC, Buchman GW, Boucias DG, Scharf ME cDNAs encoding two gut laccase isoforms (RfLacA and RfLacB) were sequenced from the termite Reticulitermes flavipes. Phylogenetic analyses comparing translated R. flavipes laccases to 67 others from prokaryotes and eukaryotes indicate that the R. flavipes laccases are evolutionarily unique. Alignments with crystallography-verified laccases confirmed that peptide motifs involved in metal binding are 100% conserved in both isoforms. Laccase transcripts and phenoloxidase activity were most abundant in symbiont-free salivary gland and foregut tissue, indicating that the genes and activities are host-derived. Using a baculovirus-insect expression system, the two isofo... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3869368 Thu, 05 Aug 2010 23:00:00 +0100 3869368 http://www.medworm.com/index.php?rid=3869367&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20691785%26dopt%3DAbstract Authors: Eum JH, Bottjen RC, Pruijssers AJ, Clark KD, Strand MR The polydnavirus Microplitis demolitor bracovirus (MdBV) encodes 13 genes that share homology with classical protein tyrosine phosphatases (PTPs). Prior sequence analysis suggested that five members of the MdBV PTP gene family (ptp-H2, -H3, -H5, -N1 and -N2) encode PTPs, seven family members encode pseudophosphatases, and one family member is a pseudogene. Prior experimental studies further implicated PTP-H2 in disabling the function of host hemocytes following infection by MdBV. Here we report expression of PTP-H2 and selected mutants in Escherichia coli cells as non-fusion or thioredoxin-fusion proteins. Following purification by nickel affinity chromatography, the full-length and mutant proteins ran as single bands of p... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3869367 Thu, 05 Aug 2010 23:00:00 +0100 3869367 http://www.medworm.com/index.php?rid=3869366&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20692340%26dopt%3DAbstract Authors: Takasu Y, Kobayashi I, Beumer K, Uchino K, Sezutsu H, Sajwan S, Carroll D, Tamura T, Zurovec M Targeted mutagenesis is one of the key methods for functional gene analysis. A simplified variant of gene targeting uses direct microinjection of custom-designed Zinc Finger Nuclease (ZFN) mRNAs into Drosophila embryos. To evaluate the applicability of this method to gene targeting in another insect, we mutagenized the Bombyx mori epidermal color marker gene BmBLOS2, which controls the formation of uric acid granules in the larval epidermis. Our results revealed that ZFN mRNA injection is effective to induce somatic, as well as germline, mutations in a targeted gene by non-homologous end joining (NHEJ). The NHEJ mutations caused by ZFN lack end-filling and blunt ligation products, an... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3869366 Wed, 04 Aug 2010 23:00:00 +0100 3869366 http://www.medworm.com/index.php?rid=3869365&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20692341%26dopt%3DAbstract Authors: Serrano-Pinto V, Acosta-Pérez M, Luviano-Bazán D, Hurtado-Sil G, Batista CV, Martínez-Barnetche J, Lánz-Mendoza H The main vector for transmission of malaria in Mexico is the Anopheles albimanus mosquito. The midgut of disease-transmitting mosquitoes carries out a variety of functions that are related to blood feeding. We analyzed the midgut of An. albimanus infected with Plasmodium berghei (resistant mosquito) using a proteomic approach to identify putative short peptides that are enriched in the midgut after blood feeding. Mosquito midguts were analyzed by two-dimensional electrophoresis to determine the changes in protein profiles. We identified 21 spot proteins that are differentially expressed in the blood of mosquitoes during the immune challenge. Molecular w... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3869365 Wed, 04 Aug 2010 23:00:00 +0100 3869365 http://www.medworm.com/index.php?rid=3869370&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20691782%26dopt%3DAbstract Authors: Wang HL, Liénard MA, Zhao CH, Wang CZ, Löfstedt C The Chinese tussah silkworm, Antheraea pernyi (Lepidoptera: Saturniidae) produces a rare dienoic sex pheromone composed of (E,Z)-6,11-hexadecadienal, (E,Z)-6,11-hexadecadienyl acetate and (E,Z)-4,9-tetradecadienyl acetate, and for which the biosynthetic routes are yet unresolved. By means of gland composition analyses and in vivo labeling we evidenced that pheromone biosynthesis towards the immediate dienoic gland precursor, the (E,Z)-6,11-hexadecadienoic acid, involves desaturation steps with (6) and (11) regioselectivity. cDNA cloning of pheromone gland desaturases and heterologous expression in yeast demonstrated that the 6,11-dienoic pheromone is generated from two biosynthetic routes implicating a (6) and (11) desatu... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3869370 Tue, 03 Aug 2010 23:00:00 +0100 3869370 http://www.medworm.com/index.php?rid=3869369&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20691783%26dopt%3DAbstract Authors: Silva MC, Terra WR, Ferreira C Trehalase (EC 3.2.1.28) hydrolyzes only alpha, alpha - trehalose and is present in a variety of organisms, but is most important in insects and fungi. Crystallographic data showed that bacterial trehalase has D312 and E496 as the catalytical residues and three Arg residues in the active site. Those residues have homologous in all family 37 trehalases including S. frugiperda trehalase (D322, E520, R169, R227, R287). To test the role of these residues, mutants of trehalase were produced. All mutants were at least four orders of magnitude less active than wild type trehalase and no structural difference between these mutants and wild type enzyme were discernible by circular dichroism. D322A and E520 pH-activity profile lacked the alkaline arm and th... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3869369 Tue, 03 Aug 2010 23:00:00 +0100 3869369 http://www.medworm.com/index.php?rid=3833607&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20688162%26dopt%3DAbstract Authors: Zhu Y, Ragan EJ, Kanost MR Leucine-rich repeat containing proteins are involved in immune response in many capacities. In insects, these include Toll-like receptors and the Anopheles gambiae proteins APL1 and LRIM1. Here we describe the identification and characterization of leureptin, a novel extracellular protein with 13 leucine-rich repeats from hemolymph of the insect Manduca sexta. After injection of bacteria, leureptin mRNA level increased in fat body, but protein levels in plasma decreased, an indication that leureptin is consumed during the immune response. Leureptin bound to bacterial lipopolysaccharide (LPS). Microscopy using leureptin antiserum showed that leureptin associates with hemocytes after injection of bacteria, an indication that leureptin is involved in he... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3833607 Sun, 01 Aug 2010 23:00:00 +0100 3833607 http://www.medworm.com/index.php?rid=3764638&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20633649%26dopt%3DAbstract Authors: Shukla JN, Nagaraju J Doublesex (dsx) is the bottom most gene of the sex determination cascade of Drosophila melanogaster. The pre-mRNA of dsx splices to produce male- and female-specific transcripts which code for the male- and female-specific proteins, respectively. dsx homologues have been characterized from different (many in Diptera, two in Hypmenoptera and only one in Lepidoptera) insect species. Sex-specific splice forms of dsx pre-mRNA in all these species code for one male and one female-specific DSX proteins, which regulate the downstream target genes responsible for sex-specific characters. In the present study we have cloned and characterized the dsx homologues from two saturniid silkmoths, Antheraea assama and A. mylitta. The divergence time between Saturniidae an... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3764638 Sun, 11 Jul 2010 23:00:00 +0100 3764638 http://www.medworm.com/index.php?rid=3764639&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20624461%26dopt%3DAbstract Authors: An C, Kanost MR Insect immune responses include prophenoloxidase (proPO) activation and Toll pathway initiation, which are mediated by serine proteinase cascades and regulated by serpins. Manduca sexta hemolymph proteinase 6 (HP6) is a component of both pathways. It cleaves and activates proPO activating proteinase 1 (PAP1) and hemolymph proteinase 8 (HP8), which activates proSpätzle. Inhibitors of HP6 could have the capability of regulating both of these innate immune proteinase cascade pathways. Covalent complexes of HP6 with serpin-4 and serpin-5 were previously isolated from M. sexta plasma using immunoaffinity chromatography with serpin antibodies. We investigated the inhibition of purified, recombinant HP6 by serpin-4 and serpin-5. Both serpin-4 and serpin-5 formed SD... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3764639 Thu, 08 Jul 2010 23:00:00 +0100 3764639 http://www.medworm.com/index.php?rid=3733437&cid=s_35630_60_f&fid=35630&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20599616%26dopt%3DAbstract Authors: Liu S, Ding Z, Zhang C, Yang B, Liu Z RNA interference (RNAi) is a powerful strategy for gene function study in insects. Here, we described the development of a RNAi technique by microinjection of double-stranded RNA (dsRNA) in the brown planthopper Nilaparvata lugens. Based on the mortality and RNAi efficiency criteria, the conjunctive between prothorax and mesothorax was selected as the injection site and 50 nl as injection volume. Three genes with different expression patterns were selected to evaluate the RNAi efficiency. A comparable 40% decrease of gene expression was observed at the 4th day after injection for the ubiquitously expressed calreticulin and the gut specific cathepsin-B genes, but only 25% decrease at the 5th day for the central nervous system specific Nlbet... Insect Biochemistry and Molecular Biology journals http://www.medworm.com/rss/comments.php?id=3733437 Thu, 24 Jun 2010 23:00:00 +0100 3733437