Zoology
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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 27.
Plasticity in sexual size dimorphism and Rensch’s rule in Mediterranean blennies (Blenniidae)
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W. Lengkeek, K. Didderen, I. M. Côté, E. M. van der Zee, R. C. Snoek, and J. D. Reynolds - Comparative analyses of sexual size dimorphism (SSD) across species have led to the discovery of Rensch’s rule. This rule states that SSD increases with body...
Source: Canadian Journal of Zoology - October 1, 2008 Category: Zoology Source Type: journals
Degeneration of the midgut epithelium in Epilachna cf. nylanderi (Insecta, Coccinellidae): apoptosis, autophagy, and necrosisEmail this article to a colleague.
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This study investigates mechanisms of adaptation to metal toxicity peculiar to the midgut epithelium of Epilachna cf. nylanderi (Mulsant, 1850) (Coccinellidae). This species of beetle...
Source: Canadian Journal of Zoology - October 1, 2008 Category: Zoology Source Type: journals
Ecological factors influencing the spatial pattern of Canada lynx relative to its southern range edge in Alberta, CanadaEmail this article to a colleague.
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We examined the spatial pattern of Canada lynx (Lynx canadensis Kerr, 1792) relative to its southern range edge at the boreal plains - prairie ecotone in...
Source: Canadian Journal of Zoology - October 1, 2008 Category: Zoology Source Type: journals
Vibratory interneurons in the non-hearing cave cricket indicate evolutionary origin of sound processing elements in Ensifera.Email this article to a colleague.
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Tympanal hearing organs in the front tibiae of ensiferan insects supposedly evolved from vibration-sensitive tibial organs (TO), like those in the cave cricket Troglophilus neglectus (Rhaphidophoridae). If this is true, one expects to find interneurons in the cave cricket that are homologous to auditory neurons from hearing Ensifera. Therefore, we examined the central projections of the foreleg TO of the cave cricket, as well as morphology and response properties of interneurons responding to foreleg vibration. Sensory axons of the TO adjoined to the "tympanal nerve" terminate in the equivalent portion of the ring trac...
Source: Zoology - October 1, 2008 Category: Zoology Authors: Stritih N, Stumpner A Tags: Zoology (Jena) Source Type: journals
Testis size, sperm characteristics and testosterone concentrations in four species of shrews (Mammalia, Soricidae).Email this article to a colleague.
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The aim of this study was to establish and compare the sperm characteristics in four shrew species in the context of the sperm competition hypothesis. As expected, the large relative testis size in promiscuous species was associated with a high number of cauda epididymal spermatozoa and a high concentration of circulating testosterone. In addition, in Sorex and Neomys, species with high intensity of sperm competition, the spermatozoa stored in cauda epididymis were characterized by high percentage of progressive motility whereas in Crocidura and Suncus, the cauda epididymal spermatozoa were motile but with very low per...
Source: Animal Reproduction Science - October 1, 2008 Category: Zoology Authors: Parapanov RN, Nusslé S, Crausaz M, Senn A, Hausser J, Vogel P Tags: Anim Reprod Sci Source Type: journals
Bayesian estimates of genetic parameters for pre-conception traits, gestation length and calving interval in beef cattle.Email this article to a colleague.
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A total of 5253 records obtained from 2081 Rubia Gallega beef cows managed using artificial insemination as the only reproduction system were analysed to estimate genetic parameters for days to first insemination (DFI), days from first insemination to conception (FIC), number of inseminations per conception (IN), days open (DO), gestation length (GL) and calving interval (CI) via multitrait Bayesian procedures. Estimates of the mean of posterior distribution of the heritability of DFI, FIC, IN, DO, GL and CI were, respectively, 0.050, 0.078, 0.071, 0.053, 0.037 and 0.085 and the corresponding estimates for repeatabilit...
Source: Animal Reproduction Science - October 1, 2008 Category: Zoology Authors: Yagüe G, Goyache F, Becerra J, Moreno C, Sánchez L, Altarriba J Tags: Anim Reprod Sci Source Type: journals
Effect of selenium and vitamin E supplementation during the late pregnancy on reproductive indices and milk production in heifers.Email this article to a colleague.
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A trial was performed to determine the effects of supplementation of selenium (Se) and vitamin E (VE) on reproductive indices and milk production in Holstein heifers. Sixty heifers at the late stage of gestation were randomly assigned into three groups. Heifers were balanced for age, weight and time of calving. Four and 2 weeks before expected calving the heifers were injected 0ml (C), 20ml (T1), and 40ml (T2) Se and VE supplements. Each ml contained 0.5mg Se and 50IU of d, l-alpha-tocopheryl acetate. Blood samples were collected from heifers 4 weeks before expected calving and at calving day. Se concentrations in seru...
Source: Animal Reproduction Science - October 1, 2008 Category: Zoology Authors: Moeini MM, Karami H, Mikaeili E Tags: Anim Reprod Sci Source Type: journals
Relationship of vaginal impedance with speed of return to oestrus after weaning, oestrous behaviour, parity and lactation length in cyclic sows.Email this article to a colleague.
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In conclusion, the weaning to oestrus interval, oestrus duration, parity and lactation length considerably influence the vaginal impedance in sows during peri-oestrus. The findings indicate that the impedance technique may be a useful method for a study of factors and processes that accelerate or slow down the return to oestrus after weaning and affect oestrus duration in sows.
PMID: 18990515 [PubMed - as supplied by publisher]
Source: Animal Reproduction Science - October 1, 2008 Category: Zoology Authors: Rezáč P, Křivánek I, Urban T, Borkovcová M, Pöschl M Tags: Anim Reprod Sci Source Type: journals
Elevated progesterone concentrations enhance prostaglandin F(2alpha) synthesis in dairy cows.Email this article to a colleague.
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In conclusion, dairy cows with more elevated blood P(4) concentrations released more PGF(2alpha) in response to E(2) or OT.
PMID: 19004582 [PubMed - as supplied by publisher]
Source: Animal Reproduction Science - October 1, 2008 Category: Zoology Authors: Dos Santos RM, Goissis MD, Fantini DA, Bertan CM, Vasconcelos JL, Binelli M Tags: Anim Reprod Sci Source Type: journals
A canine model of sustained atrial fibrillation induced by rapid atrial pacing and phenylephrine.Email this article to a colleague.
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In conclusion, atrial fibrillation can be maintained for at least 40 min after cessation of rapid atrial pacing in dogs with phenylephrine-induced hypertension.
PMID: 19004376 [PubMed - in process]
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Kijtawornrat A, Roche BM, Hamlin RL Tags: Comp Med Source Type: journals
Daily rhythms of serum lipids in dogs: influences of lighting and fasting cycles.Email this article to a colleague.
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We examined daily level variations of serum lipids (nonesterified fatty acids [NEFA], triglycerides, phospholipids, total cholesterol and total lipids) in healthy dogs, particularly focusing on their temporal relationship to lighting and fasting cycles. Whereas serum NEFA levels did not change across the day, levels of total lipids, total cholesterol, phospholipids, and triglycerides occurred in dogs maintained under 12:12-h light:dark cycles and fed a single meal daily. Only the rhythmic pattern of triglycerides responded to a 6 h delay in light onset, suggesting a cardinal role of a light-entrained circadian oscillator i...
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Bertolucci C, Fazio F, Piccione G Tags: Comp Med Source Type: journals
Platelets from diabetic pigs exhibit hypersensitivity to thrombin.Email this article to a colleague.
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Responses of platelets from diabetic and diabetic-hyperlipidemic pigs were studied. Pigs were made diabetic with single dose of alloxan, which acts by selectively destroying insulin-producing pancreatic beta cells thus inducing type 1 diabetes. Pigs were kept for 1 or 12 wk, during which thrombin-induced aggregation was monitored in washed platelets. The platelets showed increased sensitivity to aggregation within 1 wk of induction of diabetes. Hyperlipidemia alone for 12 wk did not increase platelet hypersensitivity, but hyperlipidemia together with diabetes significantly increased thrombin-induced platelet aggregatio...
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Shukla SD, Kansra SV, Reddy MA, Shukla SM, Klachko DM, Sturek M Tags: Comp Med Source Type: journals
Pathologic findings in rabbit models of hereditary hypertriglyceridemia and hereditary postprandial hypertriglyceridemia.Email this article to a colleague.
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This study was designed to investigate the histopathologic features of TGH and PHT rabbits. TGH rabbits showed advanced aortic atherosclerosis, accompanied by intimal thickening of coronary and renal arteries, fatty liver changes, and xanthoma. PHT rabbits demonstrated aortic intimal thickening and hepatic fatty degeneration. The results of this study suggest that TGH and PHT rabbits are useful animal models for studying human hyperlipidemia and metabolic syndrome and the cardiovascular diseases that result from these conditions.
PMID: 19004373 [PubMed - in process]
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Mitsuguchi Y, Ito T, Ohwada K Tags: Comp Med Source Type: journals
Differential susceptibility of SD and CD rats to a novel rat theilovirus.Email this article to a colleague.
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Antibodies to rat theilovirus (RTV) have been detected in rats for many years because of their serologic crossreactivity with strains of Theiler murine encephalomyelitis virus (TMEV) of mice. Little information exists regarding this pathogen, yet it is among the most common viruses detected in serologic surveys of rats used in research. In the study reported here, a novel isolate of RTV, designated RTV1, was cultured from the feces of infected rats. The RTV1 genome contained 8094 nucleotides and had approximately 95% identity with another rat theilovirus, NSG910, and 73% identity with TMEV strains. In addition, the gen...
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Drake MT, Riley LK, Livingston RS Tags: Comp Med Source Type: journals
Discrimination of auditory stimuli during isoflurane anesthesia.Email this article to a colleague.
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Deep isoflurane anesthesia initiates a burst suppression pattern in which high-amplitude bursts are preceded by periods of nearly silent electroencephalogram. The burst suppression ratio (BSR) is the percentage of suppression (silent electroencephalogram) during the burst suppression pattern and is one parameter used to assess anesthesia depth. We investigated cortical burst activity in rats in response to different auditory stimuli presented during the burst suppression state. We noted a rapid appearance of bursts and a significant decrease in the BSR during stimulation. The BSR changes were distinctive for the differ...
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Rojas MJ, Navas JA, Greene SA, Rector DM Tags: Comp Med Source Type: journals
Helicobacter infection decreases reproductive performance of IL10-deficient mice.Email this article to a colleague.
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Infections with a variety of Helicobacter species have been documented in rodent research facilities, with variable effects on rodent health. Helicobacter typhlonius has been reported to cause enteric disease in immunodeficient and IL10(-/-) mice, whereas H. rodentium has only been reported to cause disease in immunodeficient mice coinfected with other Helicobacter species. The effect of Helicobacter infections on murine reproduction has not been well studied. The reproductive performance of C57BL/6 IL10(-/-) female mice intentionally infected with H. typhlonius, H. rodentium, or both was compared with that of age-matc...
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Sharp JM, Vanderford DA, Chichlowski M, Myles MH, Hale LP Tags: Comp Med Source Type: journals
Study of a Bordetella hinzii isolate from a laboratory mouse.Email this article to a colleague.
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This report describes the first isolation of B. hinzii from a mouse and confirms the organism's pathogenicity in mice.
PMID: 19004369 [PubMed - in process]
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Hayashimoto N, Yasuda M, Goto K, Takakura A, Itoh T Tags: Comp Med Source Type: journals
Plasma levels of nitrite and nitrate in early and recent classes of fish.Email this article to a colleague.
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This study provides an expanded comparative view of plasma NO, levels across 3 groups of early fish. The data obtained suggest a nitric oxide system in early and modern fish.
PMID: 19004368 [PubMed - in process]
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Williams DA, Flood MH, Lewis DA, Miller VM, Krause WJ Tags: Comp Med Source Type: journals
The laboratory rat as an animal model for osteoporosis research.Email this article to a colleague.
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Osteoporosis is an important systemic disorder, affecting mainly Caucasian women, with a diverse and multifactorial etiology. A large variety of animal species, including rodents, rabbits, dogs, and primates, have been used as animal models in osteoporosis research. Among these, the laboratory rat is the preferred animal for most researchers. Its skeleton has been studied extensively, and although there are several limitations to its similarity to the human condition, these can be overcome through detailed knowledge of its specific traits or with certain techniques. The rat has been used in many experimental protocols ...
Source: Comparative Medicine - October 1, 2008 Category: Zoology Authors: Lelovas PP, Xanthos TT, Thoma SE, Lyritis GP, Dontas IA Tags: Comp Med Source Type: journals
Early jawless vertebrates and cyclostome origins.Email this article to a colleague.
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Undoubted fossil lampreys are recorded since the Late Devonian (358 Ma), and probable fossil hagfishes since the Late Carboniferous (300 Ma), but molecular clock data suggest a much earlier divergence times for the two groups. In the early 20(th) century, hagfishes and lampreys were generally thought to have diverged much later from unknown ancestral cyclostomes, in turn derived through 'degeneracy' from some Paleozoic armored jawless vertebrates, or 'ostracoderms.' However, current vertebrate phylogenies suggest that most, if not all, 'ostracoderms' are in fact jawless stem gnathostomes, which retain certain features ...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Janvier P Tags: Zoolog Sci Source Type: journals
Glycoprotein hormone receptors in the sea lamprey Petromyzon marinus.Email this article to a colleague.
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Secretion of the pituitary glycoprotein hormones (GpH) follitropin, lutropin, and thyrotropin in vertebrates is the main mechanism by which neuroendocrine signals are propagated at the level of the peripheral glands, gonads and thyroid. Receptors of these hormones (glycoprotein hormone receptors, GpH-R) evolved from a common ancestor through gene duplication and subsequent functional divergence during the split of gnathostomes from their agnathan ancestors. Here we review the properties of two novel receptors closely related to gnathostome GpH-Rs identified in the sea lamprey. Although these are the oldest members of t...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Freamat M, Sower SA Tags: Zoolog Sci Source Type: journals
The hagfish pituitary gland and its putative adenohypophysial hormones.Email this article to a colleague.
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The pituitary gland is present in all vertebrates, from agnathans (jawless fishes) to mammals, but not in invertebrates. Hagfishes, which lack both jaws and vertebrae, are considered the most primitive vertebrate known, living or extinct. Accordingly, studies on hagfishes are indispensable for understanding the origin and evolution of the pituitary hormones. Nevertheless, little is known about the hagfish adenohypophysial hormones. Our recent immunohistochemical and lectin histochemical studies have revealed that gonadotropin (GTH), adrenocorticotropin (ACTH), and growth hormone (GH) are present in the hagfish pituitar...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Nozaki M Tags: Zoolog Sci Source Type: journals
Development of the lamprey central nervous system, with reference to vertebrate evolution.Email this article to a colleague.
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Vertebrate brains are highly organized structures that show remarkable diversity throughout animal groups. The agnathans, which diverged from the gnathostomes early in the evolution of the vertebrates, occupy a key phylogenetic position from which to clarify the origin and evolution of the brain. We studied the developing lamprey brain and compared its developmental plan with that of the gnathostomes, in order to reconstruct the evolutionary processes of the vertebrate brain. We found that the lamprey brain has the basic molecular mechanisms necessary to form neuromeric compartments, and that its mesencephalon and dien...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Watanabe A, Hirano S, Murakami Y Tags: Zoolog Sci Source Type: journals
The lancelet and ammocoete mouths.Email this article to a colleague.
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The evolutionary history of the vertebrate mouth has long been an intriguing issue in comparative zoology. When the prevertebrate state was considered, the oral structure in adult lancelets (amphioxus) was traditionally referred to because of its general similarity to that of the ammocoete larva of lampreys. The larval mouth in lancelets, however, shows a peculiar developmental mode. Reflecting this, the affinity of the lancelet mouth has long been argued, but is still far from a consensus. The increase in available data from molecular biology, comparative developmental biology, paleontology, and other related fields m...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Yasui K, Kaji T Tags: Zoolog Sci Source Type: journals
Developmental biology of hagfishes, with a report on newly obtained embryos of the Japanese inshore hagfish, Eptatretus burgeri.Email this article to a colleague.
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The apparently primitive features of hagfishes are recognized as a crucial problem in the study of vertebrate evolution, although the monophyletic relationship between these animals and lampreys has been confirmed by large amounts of molecular data, including genome and EST sequences. To solve this problem requires knowledge of the developmental biology of hagfishes. We attempted to obtain embryos from the Japanese inshore hagfish ( Eptatretus burgeri ) and succeeded in preparing several nicely fixed embryos. Based on detailed histological observations and comparison of gene expression patterns with those of convention...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Ota KG, Kuratani S Tags: Zoolog Sci Source Type: journals
The origin of the vertebrate jaw: neoclassical ideas versus newer, development-based ideas.Email this article to a colleague.
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Here I consider ways to test two hypotheses of the origin of jawed vertebrates: my neoclassical hypothesis, which derived from comparative morphology; and the heterotopic hypothesis, which derives from modern developmental findings. The heterotopic hypothesis, unlike the neoclassical hypothesis, says that major developmental changes had to occur before the upper jaws could evolve: a caudal shift in the expression domains of genes that pattern oral structures; and the loss of ancestral, lamprey-like upper lips. To test whether these did occur, I propose studies on the development of chondrichthyans (sharks and chimaeroi...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Mallatt J Tags: Zoolog Sci Source Type: journals
SoxE, Type II collagen, and evolution of the chondrogenic neural crest.Email this article to a colleague.
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Vertebrates are defined by the presence of the neural crest. These cells contribute to the increased complexity of vertebrates relative to non-vertebrate chordates. It is widely accepted that an increase in vertebrate complexity is also related to gene duplications that occurred at the base of vertebrates and may be related to the origin of the neural crest. Study of the development of one neural crest derivative, pharyngeal cartilage, in the lamprey and comparison to chondrogenesis in other chordates may provide clues regarding acquisition of a chondrogenic fate by the neural crest. The transcription factor Sox9 is th...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: McCauley DW Tags: Zoolog Sci Source Type: journals
Whole-mount observation of pharyngeal and trabecular cartilage development in lampreys.Email this article to a colleague.
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Because the jaw is thought to have evolved as a dorsal-ventral articulation of the anterior pharyngeal arch, knowledge of developmental patterning in the pharyngeal arch is critical to understanding the origin and evolution of the jaw in gnathostomes. It is particularly important to determine whether Agnatha already possessed developmental polarity along the dorsal-ventral axis of the pharyngeal arch. We used the Weigert staining method to examine the development of cartilage in whole-mount lamprey specimens. We found that although the transverse rods showed symmetrical patterning along the dorsal-ventral axis, the hyp...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Yao T, Ohtani K, Wada H Tags: Zoolog Sci Source Type: journals
Two types of antigen receptor systems in vertebrates.Email this article to a colleague.
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Extant jawless vertebrates, represented by lampreys and hagfishes, have innate immune receptors with variable domains structurally resembling those of T/B-cell receptors. However, they appear to lack cardinal elements of adaptive immunity shared by all jawed vertebrates: major histocompatibility complex molecules and T/B-cell receptors. Thus, it was widely believed that adaptive immunity is unique to jawed vertebrates. Recently, this belief was overturned by the discovery of agnathan antigen receptors named variable lymphocyte receptors. These receptors generate diversity in their antigen-binding sites through assembli...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Kasahara M, Kasamatsu J, Sutoh Y Tags: Zoolog Sci Source Type: journals
Insights into cyclostome phylogenomics: pre-2R or post-2R.Email this article to a colleague.
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Interest in understanding the transition from prevertebrates to vertebrates at the molecular level has resulted in accumulating genomic and transcriptomic sequence data for the earliest groups of extant vertebrates, namely, hagfishes (Myxiniformes) and lampreys (Petromyzontiformes). Molecular phylogenetic studies on species phylogeny have revealed the monophyly of cyclostomes and the deep divergence between hagfishes and lampreys (more than 400 million years). In parallel, recent molecular phylogenetic studies have shed light on the complex evolution of the cyclostome genome. This consists of whole genome duplications,...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Kuraku S Tags: Zoolog Sci Source Type: journals
ParaHox cluster evolution--hagfish and beyond.Email this article to a colleague.
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Abstract The ParaHox genes comprise three Hox-related homeobox gene families, found throughout the animals. They were first discovered in the invertebrate chordate amphioxus, where they are tightly clustered. In this paper we carry out a comparative review of ParaHox gene cluster organization among the deuterostomes, and discuss how the recently published hagfish ParaHox clusters fit into current theories about the evolution of this group of genes.
PMID: 19267630 [PubMed - in process]
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: Furlong RF, Mulley JF Tags: Zoolog Sci Source Type: journals
Cyclostome studies in the context of vertebrate evolution.Email this article to a colleague.
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The proceedings in this volume follow from the 15(th) Center for Developmental Biology meeting on "Advances in Cyclostome Research" that we organized. The meeting was held at the CDB RIKEN Kobe Institute on 24 and 25 January 2008 with support from the CDB. Jawless vertebrates have been of interest to embryologists and comparative morphologists for more than a century. While the comparative morphology among lampreys, hagfishes, and gnathostomes has long been recognized in contributing to understanding the origin of jaws and other gnathostome traits, the availability of modern molecular methods has rekindled interest in ...
Source: Zoological Science - October 1, 2008 Category: Zoology Authors: McCauley DW, Kuratani S Tags: Zoolog Sci Source Type: journals
Evidence for Hox-specified positional identities in adult vasculatureEmail this article to a colleague.
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Conclusions:
The data support a conceptual model of Hox-specified positional identities in adult blood vessels, which is of likely relevance for understanding the mechanisms underlying regional physiological diversities in the cardiovascular system. The data also demonstrate that conventional Hox reporter gene mice are useful tools for visualizing complex Hox expression patterns in the vascular network that might be unattainable otherwise. Finally, these mice are a resource for the isolation and phenotypic characterization of specific subpopulations of vascular cells marked by distinct Hox expression profiles.
Source: BMC Developmental Biology - Latest articles - September 30, 2008 Category: Zoology Authors: Nathanael D Pruett, Richard P Visconti, Donna F Jacobs, Dimitri Scholz, Tim McQuinn, John P Sundberg and Alexander Awgulewitsch Source Type: journals
Termites, hemimetabolous diploid white ants?Email this article to a colleague.
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Ants and termites are the most abundant animals on earth. Their ecological success is attributed to their social life. They live in colonies consisting of few reproducing individuals, while the large majority of colony members (workers/soldiers) forego reproduction at least temporarilly. Despite their apparent resemblance in social organisation, both groups evolved social life independently. Termites are basically social cockroaches, while ants evolved from predatory wasps. In this review, I will concentrate on termites with an ancestral life type, the wood-dwelling termites, to compare them with ants. Their different ance...
Source: Frontiers in Zoology - September 29, 2008 Category: Zoology Authors: Judith Korb Source Type: journals
Effects of timing of nest entry and body size on the fertilization success of alternative male reproductive phenotypes of masu salmon (Oncorhynchus masou)Email this article to a colleague.
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M. Watanabe, S. Takamura, and K. Maekawa - Using a natural population of masu salmon (Oncorhynchus masou (Brevoort, 1856)) in a stream of Shikaribetsu Lake, Hokkaido, Japan, we combined behavioural observations with genetic...
Source: Canadian Journal of Zoology - September 25, 2008 Category: Zoology Source Type: journals
Specific dynamic action, apparent assimilation efficiency, and digestive rate in an arboreal pitviper, Trimeresurus stejnegeri stejnegeriEmail this article to a colleague.
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Tein-Shun Tsai, How-Jing Lee, and Ming-Chung Tu - The major aims of this study were to assess the effects of temperature (15 - 35 °C) and meal size (less than 30% snake mass) on the metabolism...
Source: Canadian Journal of Zoology - September 25, 2008 Category: Zoology Source Type: journals
Amphibian predation on larval mosquitoesEmail this article to a colleague.
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Sarah E. DuRant and William A. Hopkins - Mosquitoes (Culex pipiens L., 1758) are important vectors for diseases of both wildlife and humans. Understanding how natural factors influence mosquito abundance may provide insights...
Source: Canadian Journal of Zoology - September 25, 2008 Category: Zoology Source Type: journals
Distinct roles of Shh and Fgf signaling in regulating cell proliferation during zebrafish pectoral fin developmentEmail this article to a colleague.
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Conclusions:
Previous studies have shown that both Shh and Fgf signaling are crucial for outgrowth of the vertebrate limb. The results presented here show that the role of Shh in this process is indirect, and is mediated by its effect on Fgf signaling. By contrast, the activity of the Fgf pathway affects proliferation directly and independently of its effect on Shh. These results show that Fgf signaling is of primary importance in directing outgrowth of the limb bud, and clarify the role of the Shh-Fgf feedback loop in regulating proliferation.
Source: BMC Developmental Biology - Latest articles - September 23, 2008 Category: Zoology Authors: Sergey V Prykhozhij and Carl J Neumann Source Type: journals
Cell-Extracellular Matrix Interactions Regulate Neural Differentiation of Human Embryonic Stem CellsEmail this article to a colleague.
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Conclusion:
We defined laminin as a key ECM molecule to enhance neural progenitor generation, expansion and differentiation into neurons from hESCs. The cell-laminin interactions involve alpha6beta1 integrin receptors implicating a possible role of laminin/alpha6beta1 integrin signaling in directed neural differentiation of hESCs. Since laminin acts in concert with other ECM molecules in vivo, evaluating cellular responses to the composition of the ECM is essential to further clarify the role of cell-matrix interactions in neural derivation of hESCs.
Source: BMC Developmental Biology - Latest articles - September 22, 2008 Category: Zoology Authors: Wu Ma, Tahereh Tavakoli, Eric Derby, Yevgeniya Serebryakova, Mahandra S Rao and Mark P Mattson Source Type: journals
Generation of diverse neuronal subtypes in cloned populations of stem-like cellsEmail this article to a colleague.
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Conclusions:
The data indicate that genes involved in positional determination are activated along with pro-neuronal genes in conditions excluding any outside influences. Interactions among progenies of one cell derived neural stem cells are sufficient for the activation of diverse region specific genes and initiate different routes of neuronal specification.
Source: BMC Developmental Biology - Latest articles - September 22, 2008 Category: Zoology Authors: Balazs V Varga, Nora Hadinger, Elen Gocza, Vered Dulberg, Kornel Demeter, Emilia Madarasz and Balazs Herberth Source Type: journals
Cranial shape differentiation in three closely related delphinid cetacean species: Insights into evolutionary history.Email this article to a colleague.
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The present study investigates the pattern of differentiation of cranial shape in three closely related delphinid cetacean species of the complex Delphinus-Stenella-Tursiops: Delphinus delphis, Stenella coeruleoalba and Tursiops truncatus. Dorsal and ventral aspects of the cranium were analysed using landmark-based geometric morphometric methods. While there was no evidence of sexual dimorphism for shape or size, multivariate statistical analyses showed that there were interspecific differences in skull morphology. Skull shape differences between the three studied species were related with cranial width and differences...
Source: Zoology - September 22, 2008 Category: Zoology Authors: Amaral AR, Coelho MM, Marugán-Lobón J, James Rohlf F Tags: Zoology (Jena) Source Type: journals
Tool use as a way to assess cognition: how do captive chimpanzees handle the weight of the hammer when cracking a nut?Email this article to a colleague.
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Tool use in apes has been considered a landmark in cognition. However, while most studies concentrate on mental operations, there are very few studies of apes' cognition as expressed in manual skills. This paper proposes theoretical and methodological considerations on movement analysis as a way of assessing primate cognition. We argue that a privileged way of appraising the characteristics of the cognitive abilities involved in tool use lies at the functional level. This implies that we focus on how the action proceeds, and more precisely, on how the functional characteristics of the task are generated. To support our...
Source: Animal Cognition - September 20, 2008 Category: Zoology Authors: Bril B, Dietrich G, Foucart J, Fuwa K, Hirata S Tags: Anim Cogn Source Type: journals
An overview and comparative analysis of singing on the nest in North American birdsEmail this article to a colleague.
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M. Leonard - Bird song is used to defend territories and attract mates and tends to make the singer conspicuous. Singing on the nest (SOTN) has been mentioned...
Source: Canadian Journal of Zoology - September 19, 2008 Category: Zoology Source Type: journals
Female-limited polymorphism in a widespread damselfly: morph frequencies, male density, and phenotypic similarity of andromorphs to malesEmail this article to a colleague.
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H. Van Gossum, T. Robb, M. R. Forbes, and L. Rasmussen - In several animal species, one male type coexists with two to several female types, a polymorphism often explained in the context of sexual selection. Where...
Source: Canadian Journal of Zoology - September 19, 2008 Category: Zoology Source Type: journals
Hydrological stability and otter trophic diversity: a scale-insensitive pattern?Email this article to a colleague.
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M. Clavero, J. Prenda, F. Blanco-Garrido, and M. Delibes - Two recent works related Eurasian otter (Lutra lutra (L., 1758)) trophic patterns over large areas with the stability of aquatic ecosystems. Higher levels of instability...
Source: Canadian Journal of Zoology - September 19, 2008 Category: Zoology Source Type: journals
Influence of the breed of bull (Bos taurus indicus vs. Bos taurus taurus) and the breed of cow (Bos taurus indicus, Bos taurus taurus and crossbred) on the resistance of bovine embryos to heat.Email this article to a colleague.
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In conclusion, the present results indicate that Nelore embryos (indicus) are more resistant to heat shock than Holstein (taurus) at early stages of in vitro development, and that embryos become more thermo-tolerant as development proceeds. Additionally, the resistance to heat shock was a result of the genetic contribution from both oocyte and spermatozoa.
PMID: 18980815 [PubMed - as supplied by publisher]
Source: Animal Reproduction Science - September 19, 2008 Category: Zoology Authors: Eberhardt BG, Satrapa RA, Capinzaiki CR, Trinca LA, Barros CM Tags: Anim Reprod Sci Source Type: journals
A morphological reappraisal of Tubifex blanchardi Vejdovský, 1891 (Clitellata: Tubificidae)Email this article to a colleague.
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This study also supports the idea that T. blanchardi and T. bergi (Hrabě, 1935), another species closely related to T. tubifex, are not conspecific. The observed morphological differences between allopatric populations of T. tubifex are discussed.
Source: Acta Zoologica - September 18, 2008 Category: Zoology Authors: Roberto Marotta, Angelica Crottini, Valeria Prada, Marco Ferraguti Source Type: journals
An in vivo reporter of BMP signaling in organogenesis reveals targets in the developing kidneyEmail this article to a colleague.
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Conclusions:
Transgenic reporters driven by control elements from BMP responsive genes such as Id1 offer significant advantages in sensitivity and consistency over immunostaining for studies of BMP pathway activation. They also provide opportunities for analysis of BMP signaling in organ and primary cell cultures subjected to experimental manipulation. Using such a reporter, we made the surprising finding that SMAD dependent BMP signaling is inactive in nephron progenitors, and that these cells are refractory to activation by applied growth factors. Furthermore, we find that the BMP pathway is not normally active in collec...
Source: BMC Developmental Biology - Latest articles - September 18, 2008 Category: Zoology Authors: Ulrika Blank, Marianne L Seto, Derek C Adams, Don M Wojchowski, Michele J Karolak and Leif Oxburgh Source Type: journals
Evolution of the shell coat and yolk in amniotes: a marsupial perspective.Email this article to a colleague.
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Two characters distinguish oogenesis and early development in marsupials and monotremes: (1) the shell coat that persists from the zygote to somite stages in marsupials or until hatching in monotremes; and (2) the numerous, apparently almost empty vesicles that appear in primary oocytes, increase during oogenesis in marsupials and monotremes before being shed into the cleavage cavity and are preferentially distributed to the trophoblast lineage in marsupials, but comprise the latebra in monotremes. Analysis of these unusual characters used Southern analysis of genomic DNA dot blots and histology and electron microscopy...
Source: Journal of Experimental Zoology. Part B. Molecular and Developmental Evolution - September 17, 2008 Category: Zoology Authors: Menkhorst E, Nation A, Cui S, Selwood L Tags: J Exp Zoolog B Mol Dev Evol Source Type: journals
Antibodies against Salmonella is associated with reduced reproductive success in female alpine chamois (Rupicapra rupicapra)Email this article to a colleague.
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Maryline Pioz, Anne Loison, Philippe Gibert, Jean-Michel Jullien, Marc Artois, and Emmanuelle Gilot-Fromont - Microbial infections that affect reproduction are poorly studied in wildlife because reproductive disorders usually go unnoticed. However, such infections are a major concern in domestic...
Source: Canadian Journal of Zoology - September 16, 2008 Category: Zoology Source Type: journals
