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WNT5A mutations in patients with autosomal dominant Robinow syndromeEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Robinow syndrome is a skeletal dysplasia with both autosomal dominant and autosomal recessive inheritance patterns. It is characterized by short stature, limb shortening, genital hypoplasia, and craniofacial abnormalities. The etiology of dominant Robinow syndrome is unknown; however, the phenotypically more severe autosomal recessive form of Robinow syndrome has been associated with mutations in the orphan tyrosine kinase receptor, ROR2, which has recently been identified as a putative WNT5A receptor. Here, we show that two different missense mutations in WNT5A, which result in amino acid substitutions of highly conserved...
Source: Developmental Dynamics - November 14, 2009 Category: Molecular Biology Authors: Anthony D. Person, Soraya Beiraghi, Christine M. Sieben, Spencer Hermanson, Ann N. Neumann, Mara E. Robu, J. Robert Schleiffarth, Charles J. Billington Jr, Hans van Bokhoven, Jeannette M. Hoogeboom, Juliana F. Mazzeu, Anna Petryk, Lisa A. Schimmenti, Han Source Type: journals

Fusion of uniluminal vascular spheroids: A model for assembly of blood vesselsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We evaluated the self-assembly properties of uniluminal vascular spheroids having outer layers of vascular smooth muscle cells and a contiguous inner layer of endothelial cells lining a central lumen. We showed that while pairs of uniluminal vascular spheroids suspended in culture medium fused to form a larger diameter spheroidal structure, spheroids in collagen hydrogels formed elongated structures. These findings highlight the potential use of uniluminal vascular spheroids as modules to engineer blood vessels. We also demonstrate that uniluminal vascular spheroid fusion conforms to models describing the coalescence of li...
Source: Developmental Dynamics - November 13, 2009 Category: Molecular Biology Authors: Paul A. Fleming, W. Scott Argraves, Carmine Gentile, Adrian Neagu, Gabor Forgacs, Christopher J. Drake Source Type: journals

Sinusoid development and morphogenesis may be stimulated by VEGF-Flk-1 signaling during fetal mouse liver developmentEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Early morphogenesis of hepatic sinusoids was histochemically and experimentally analyzed, and the importance of VEGF-Flk-1 signaling in the vascular development was examined during murine liver organogenesis. FITC-gelatin injection experiments into young murine fetuses demonstrated that all primitive sinusoidal structures were confluent with portal and central veins, suggesting that hepatic vessel development may occur via angiogenesis. At 12.5-14.5 days of gestation, VEGF receptors designated Flk-1, especially their mature form, were highly expressed in endothelial cells of primitive sinusoidal structures and highly phosp...
Source: Developmental Dynamics - November 13, 2009 Category: Molecular Biology Authors: Yoshinori Sugiyama, Yurie Takabe, Takashi Nakakura, Shigeyasu Tanaka, Toru Koike, Nobuyoshi Shiojiri Source Type: journals

A migratory role for EphrinB ligands in avian epicardial mesothelial cellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Little is known about the molecules that mediate the attachment of proepicardial cells to the heart. Ephrins are cell surface ligands for Eph tyrosine kinase receptors, molecules known to play a role in cell adhesion and migration. Here, we detected EphrinB ligands in proepicardial and epicardial mesothelial cells (EMCs) using reverse transcriptase-polymerase chain reaction, immunoblotting, immunolocalization, and EphB-Fc binding. Aggregated EphB-Fc fragments clustered ephrinB1 ligands on living EMCs indicating that they are cell surface expressed. In vitro assays demonstrated that ephrinB ligands participate in EMC migrat...
Source: Developmental Dynamics - November 13, 2009 Category: Molecular Biology Authors: Sonia M. Wengerhoff, Amy R. Weiss, Kathryn L. Dwyer, Robert W. Dettman Source Type: journals

Visualization of myelination in GFP-transgenic zebrafishEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The insulation of axons in the vertebrate nervous system by myelin is essential for efficient axonal conduction. Myelination disruption and remyelination failure can cause human diseases, such as multiple sclerosis and hereditary myelin diseases. However, despite progress in understanding myelination regulation, many important questions remain unanswered. To investigate the mechanisms underlying myelination in vivo, we generated transgenic zebrafish expressing enhanced green fluorescent protein (EGFP) under the control of the mbp promoter. This transgenic fish displayed faithful EGFP expression in oligodendrocytes and Schw...
Source: Developmental Dynamics - November 13, 2009 Category: Molecular Biology Authors: Seung-Hyun Jung, Suhyun Kim, Ah-Young Chung, Hyun-Taek Kim, Ju-Hoon So, Jaeho Ryu, Hae-Chul Park, Cheol-Hee Kim Source Type: journals

Normal table of postembryonic zebrafish development: Staging by externally visible anatomy of the living fishEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The zebrafish is a premier model organism yet lacks a system for assigning postembryonic fish to developmental stages. To provide such a staging series, we describe postembryonic changes in several traits that are visible under brightfield illumination or through vital staining and epiflourescent illumination. These include the swim bladder, median and pelvic fins, pigment pattern, scale formation, larval fin fold, and skeleton. We further identify milestones for placing postembryonic fish into discrete stages. We relate these milestones to changes in size and age and show that size is a better indicator of developmental p...
Source: Developmental Dynamics - November 5, 2009 Category: Molecular Biology Authors: David M. Parichy, Michael R. Elizondo, Margaret G. Mills, Tiffany N. Gordon, Raymond E. Engeszer Source Type: journals

Collagen type IV and Perlecan exhibit dynamic localization in the Allantoic Core Domain, a putative stem cell niche in the murine allantoisEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A body of evidence suggests that the murine allantois contains a stem cell niche, the Allantoic Core Domain (ACD), that may contribute to a variety of allantoic and embryonic cell types. Given that extracellular matrix (ECM) regulates cell fate and function in niches, the allantois was systematically examined for Collagen type IV (ColIV) and Perlecan, both of which are associated with stem cell proliferation and differentiation. Not only was localization of ColIV and Perlecan more widespread during gastrulation than previously reported, but protein localization profiles were particularly robust and dynamic within the allan...
Source: Developmental Dynamics - November 4, 2009 Category: Molecular Biology Authors: Maria M. Mikedis, Karen M. Downs Source Type: journals

Muscleblind-like 1 is a negative regulator of TGF-[beta]-dependent epithelial-mesenchymal transition of atrioventricular canal endocardial cellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The development of the valves and septa of the heart depends on the formation and remodeling of endocardial cushions. Here, we report that the alternative splicing regulator muscleblind-like 1 (MBNL1) exhibits a regionally restricted pattern of expression in canal region endocardium and ventricular myocardium during endocardial cushion development in chicken. Knockdown of MBNL1 in atrioventricular explants leads to a transforming growth factor [beta]-dependent increase in epithelial-mesenchymal transition (EMT) of endocardial cells. This reveals a novel role for MBNL1 during embryonic development, and represents the first ...
Source: Developmental Dynamics - November 4, 2009 Category: Molecular Biology Authors: Natalie A. Vajda, Kyle R. Brimacombe, Kathryn E. LeMasters, Andrea N. Ladd Source Type: journals

Loss of Wnt8b has no overt effect on hippocampus development but leads to altered Wnt gene expression levels in dorsomedial telencephalonEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Wnt signalling proteins regulate many aspects of animal development. We have investigated the function of mouse Wnt8b during forebrain development. Wnt8b is expressed in a highly restricted pattern including the prospective hippocampus and hypothalamus. Mutant mice lacking Wnt8b are viable and healthy. The size and morphology of the hippocampus appeared normal in mutant embryos and adults, and we found no evidence of hypothalamic defects in mutants. Wnt8b is also expressed in the neurogenic region of the adult dentate gyrus, however, cell proliferation was unchanged in Wnt8b-/- mutants. Mutant embryos did, however, display...
Source: Developmental Dynamics - November 3, 2009 Category: Molecular Biology Authors: Vassiliki Fotaki, Osmany Larralde, Shaoju Zeng, David McLaughlin, Jennifer Nichols, David J. Price, Thomas Theil, John O. Mason Source Type: journals

A rapid and efficient method of genotyping zebrafish mutantsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In order to facilitate high throughput genotyping of zebrafish, we have developed a novel technique that uses High Resolution Melting Analysis (HRMA) to distinguish wild-type, heterozygous mutants and homogyzous mutants. This one hour technique removes the need for restriction enzymes and agarose gels. The generated melting curve profiles are sensitive enough to detect non-specific PCR products. We have been able to reliably genotype three classes of mutations in zebrafish, including point mutants, apchu745 (apcmcr), and p53zy7 (p53I166T), a small deletion mutant (bap28y75) and a retroviral insertion mutant (wdr43hi821a). ...
Source: Developmental Dynamics - November 3, 2009 Category: Molecular Biology Authors: John M. Parant, Stephen A. George, Rob Pryor, Carl T. Wittwer, H. Joseph Yost Source Type: journals

Characterization of molecular markers to assess cardiac cushions formation in XenopusEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The valves and septa of the mature heart are derived from the cardiac cushions, which develop from discrete swellings in two regions of developing heart tube: the atrioventricular (AV) canal and the ventricular outflow tract (OFT). In higher vertebrates, three distinct lineages contribute to the heart valves and septa, the endocardium, the myocardium, and the cardiac neural crest that will populate the cardiac jelly of the OFT. Very little is known about cardiac cushions development in amphibians. Here, we describe the expression of eight genes during key stages of cardiac cushion development in Xenopus. Among these genes,...
Source: Developmental Dynamics - November 3, 2009 Category: Molecular Biology Authors: Young-Hoon Lee, Jean-Pierre Saint-Jeannet Source Type: journals

Asator, a tau-tubulin kinase homolog in Drosophila localizes to the mitotic spindleEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We have used a yeast two-hybrid interaction assay to identify Asator, a tau-tubulin kinase homolog in Drosophila that interacts directly with the spindle matrix protein Megator. Using immunocytochemical labeling by an Asator-specific mAb as well as by transgenic expression of a GFP-labeled Asator construct, we show that Asator is localized to the cytoplasm during interphase but redistributes to the spindle region during mitosis. Determination of transcript levels using qRT-PCR suggested that Asator is expressed throughout development but at relatively low levels. By P-element excision, we generated a null or strong hypomor...
Source: Developmental Dynamics - November 3, 2009 Category: Molecular Biology Authors: Hongying Qi, Changfu Yao, Weili Cai, Jack Girton, Kristen M. Johansen, Jørgen Johansen Source Type: journals

Chondroitin sulfate expression is required for cardiac atrioventricular canal formationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Defects in cardiac valvulogenesis are a common cause of congenital heart disease, and the study of this process promises to provide mechanistic insights and lead to novel therapeutics. Normal valve development involves multiple signaling pathways, and recently roles have been identified for extracellular matrix components, including glycosaminoglycans. We, therefore, explored the role of the glycosaminoglycan chondroitin sulfate during zebrafish cardiac development. Beginning at 33 hr, there is a distinct zone of chondroitin sulfate expression in the atrioventricular (AV) boundary, in the cardiac jelly between the endocard...
Source: Developmental Dynamics - November 3, 2009 Category: Molecular Biology Authors: David S. Peal, C. Geoffrey Burns, Calum A. Macrae, David Milan Source Type: journals

Probing events with single molecule sensitivity in zebrafish and Drosophila embryos by fluorescence correlation spectroscopyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Zebrafish and Drosophila are animal models widely used in developmental biology. High-resolution microscopy and live imaging techniques have allowed the investigation of biological processes down to the cellular level in these models. Here, using fluorescence correlation spectroscopy (FCS), we show that even processes on a molecular level can be studied in these embryos. The two animal models provide different advantages and challenges. We first characterize their autofluorescence pattern and determine usable penetration depth for FCS especially in the case of zebrafish, where tissue thickness is an issue. Next, the applic...
Source: Developmental Dynamics - October 31, 2009 Category: Molecular Biology Authors: Xianke Shi, Lin Shin Teo, Xiaotao Pan, Shang-Wei Chong, Rachel Kraut, Vladimir Korzh, Thorsten Wohland Source Type: journals

Robust marking of photoreceptor cells and pinealocytes with several reporters under control of the Crx geneEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Crx is a member of the Otx family of homeobox genes with expression restricted to vertebrate retinal photoreceptor and bipolar cells as well as the pinealocytes of the pineal organ. To facilitate the visualization of Crx-expressing cells, we generated transgenic mice expressing several reporters under the control of the Crx regulatory sequences present within a bacterial artificial chromosome (BAC). These mice expand the transgenic mouse collection, which uses photoreceptor regulatory elements for reporter gene expression by providing a broader repertoire of reporter genes. In addition, because Crx is expressed very soon a...
Source: Developmental Dynamics - October 30, 2009 Category: Molecular Biology Authors: Maria Samson, Mark M. Emerson, Constance L. Cepko Source Type: journals

Cyclic Nrarp mRNA expression is regulated by the somitic oscillator but Nrarp protein levels do not oscillateEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Somites are formed progressively from the presomitic mesoderm (PSM) in a highly regulated process according to a strict periodicity driven by an oscillatory mechanism. The Notch and Wnt pathways are key components in the regulation of this somitic oscillator and data from Xenopus and zebrafish embryos indicate that the Notch-downstream target Nrarp participates in the regulation of both activities. We have analyzed Nrarp/nrarp-a expression in the PSM of chick, mouse and zebrafish embryos, and we show that it cycles in synchrony with other Notch regulated cyclic genes. In the mouse its transcription is both Wnt- and Notch-d...
Source: Developmental Dynamics - October 30, 2009 Category: Molecular Biology Authors: David Wright, Zoltan Ferjentsik, Shang-Wei Chong, Xuehui Qiu, Yun-Jin Jiang, Pascale Malapert, Olivier Pourquié, Nick Van Hateren, Stuart A. Wilson, Claudio Franco, Holger Gerhardt, J. Kim Dale, Miguel Maroto Source Type: journals

The metalloendopeptidase gene Pitrm1 is regulated by hedgehog signaling in the developing mouse limb and is expressed in muscle progenitorsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Pitrm1 is a zinc metalloendopeptidase that has been implicated in Alzheimer's disease and mitochondrial peptide degradation, but to date no major role in embryonic development has been documented. In a screen for genes regulated by hedgehog signaling in the mouse limb, we showed that expression of Pitrm1 is upregulated in response to loss of the Gli3 transcription factor. Here we confirm spatial changes in Pitrm1 expression in the Gli3 mutant mouse limb and examine Pitrm1 expression in Shh null and Ptch1 conditional deletion mouse mutants. In wild-type mice, Pitrm1 is expressed in a number of developing tissues known to be...
Source: Developmental Dynamics - October 30, 2009 Category: Molecular Biology Authors: Liam Town, Edwina McGlinn, Salvatore Fiorenza, Vicki Metzis, Natalie C. Butterfield, Joy M. Richman, Carol Wicking Source Type: journals

Kinked tail mutation results in notochord defects in heterozygotes and distal visceral endoderm defects in homozygotesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Proper formation of the anterior-posterior (AP) axis in the developing embryo is critical for the correct patterning and often survival of the organism. In the mouse, an initial step in axis establishment is the specification and migration of the distal visceral endoderm (DVE). We have identified a semi-dominant spontaneous mutation in mouse, named kinked tail (knk), which when heterozygous results in a kinky tail phenotype due to fusions and dysmorphology of the tail vertebrae. Vertebral fusions appear to be a secondary effect of notochord thickening and branching in the tail region. Homozygosity for knk results in early ...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: Deborah R. Farkas, Deborah L. Chapman Source Type: journals

Focal electroporation in ovoEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Gene expression fields in embryogenesis are spatially precise and often small, so experimental gene expression often requires similar spatial definition. For in ovo electroporation, typically a gene construct is injected into a natural body cavity in the embryo prior to electroporation. Limited control of the size and location of the electroporated field can be obtained by varying electrode placement and geometry, and by altering the miscibility and viscosity of the construct vehicle but it is difficult to tightly constrain electroporation to small regions. Electroporation of different constructs in close proximity has not...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: J. E. Simkin, S. J. McKeown, D. F. Newgreen Source Type: journals

Taste bud development and patterning in sighted and blind morphs of Astyanax mexicanusEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study compares the development of taste buds along the jaws of each morph. To determine whether cavefish have an altered onset or rate of taste bud development, we fluorescently labeled basal and receptor cells within taste buds over a developmental series. Our results show that taste bud number increases during development in both morphs. The rate of development is, however, accelerated in cavefish; a small difference in taste bud number exists at 5 dpf reaching threefold by 22 dpf. The expansion of taste buds in cavefish is, therefore, detectable after the onset of eye degeneration. This study provides important ins...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: Nirupa Varatharasan, Roger P. Croll, Tamara Franz-Odendaal Source Type: journals

Brn3a regulates the transition from neurogenesis to terminal differentiation and represses non-neural gene expression in the trigeminal ganglionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The POU-domain transcription factor Brn3a is expressed in developing sensory neurons at all levels of the neural axis, including the trigeminal ganglion, hindbrain sensory ganglia, and dorsal root ganglia. Changes in global gene expression in the trigeminal ganglion from E11.5 to E13.5 reflect the repression of early neurogenic genes, exit from the cell cycle, and initiation of the expression of definitive markers of sensory function. A majority of these developmental changes are perturbed in the trigeminal ganglia of Brn3a knockout mice. At E13.5, Brn3a-/- trigeminal neurons fail to repress a battery of developmental regu...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: Jason Lanier, Iain M. Dykes, Stephanie Nissen, S. Raisa Eng, Eric E. Turner Source Type: journals

A co-dependent requirement of xBcl9 and Pygopus for embryonic body axis development in XenopusEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The Wnt/[beta]-catenin transcriptional activation complex requires the adapter protein Pygopus (Pygo), which links the basal transcription machinery to [beta]-catenin, by its association with legless (Lgs)/ B-cell lymphoma-9 (Bcl9). Pygo was shown to be required for development in vertebrates, but the role of Lgs/Bcl9 is unknown. We identified an amphibian orthologue of Lgs/Bcl9, XBcl9, which interacted biochemically with X[beta]-catenin and XPygo2. The body axis promoting ability of X[beta]-catenin was diminished when residues required for its interaction with XBcl9 were mutated. In blastula embryos, XBcl9 was transiently...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: Mark W. Kennedy, Sang-Wook Cha, Emmanuel Tadjuidje, Phillip G. Andrews, Janet Heasman, Kenneth R. Kao Source Type: journals

Dynamic patterning at the pylorus: Formation of an epithelial intestine-stomach boundary in late fetal lifeEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In the adult mouse, distinct morphological and transcriptional differences separate stomach from intestinal epithelium. Remarkably, the epithelial boundary between these two organs is literally one cell thick. This discrete junction is established suddenly and precisely at embryonic day (E) 16.5, by sharpening a previously diffuse intermediate zone. In the present study, we define the dynamic transcriptome of stomach, pylorus, and intestinal tissues between E14.5 and E16.5. We show that establishment of this boundary is concomitant with the induction of over a thousand genes in intestinal epithelium, and these gene product...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: Xing Li, Aaron M. Udager, Chunbo Hu, Xiaotan T. Qiao, Neil Richards, Deborah L. Gumucio Source Type: journals

Planar cell polarity effector gene Fuzzy regulates cilia formation and Hedgehog signal transduction in mouseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, Fuz plays an important role in cilia formation, Hh signal transduction, and embryonic development in mammals. Developmental Dynamics, 2009. © 2009 Wiley-Liss, Inc. (Source: Developmental Dynamics)
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: Westley Heydeck, Huiqing Zeng, Aimin Liu Source Type: journals

Characterization of p70 S6 kinase 1 in early development of mouse embryosEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The mTOR kinase controls cell growth, proliferation, and survival through two distinct multiprotein complexes mTORC1 and mTORC2. p70 S6 Kinase 1 (S6K1) is characterized as downstream effector of mTOR. Until recently, the connection between S6K1 and mTORC1 /mTORC2 during the early development of mouse embryos has not been well elucidated. Here, the expression level of total S6K1 and its phosphorylation at Thr389 was determined in four phases of one-cell embryos. S6K1 was active throughout the cell cycle especially with higher activity in G2 and M phases. Rapamycin decreased the activity of M-phase promoting factor (MPF) and...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: Xiao-Yan Xu, Zhe Zhang, Wen-Hui Su, Yang Zhang, Yan-Qiu Yu, Yan-Xiao Li, Zhi-Hong Zong, Bing-Zhi Yu Source Type: journals

Postnatal lung development of rhesus monkey airways: Cellular expression of Clara cell secretory proteinEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study's rationale is to define the distribution and abundance of CCSP in the airway epithelium of the rhesus monkey during postnatal lung development using carefully controlled site-specific morphometric approaches in defined airway regions. Immunoreactive CCSP was found in nonciliated cells and mucous cells, including glands, throughout the airway epithelium at all ages, with proximal and mid-level airways having the highest labeling. Overall airway CCSP levels were low at 1 week and 1 month, doubled between 1 and 3 months, and changed little from 3 months to 3 years. Thus, the critical developmental window for CCSP ...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: John T. Coppens, Charles G. Plopper, Shannon R. Murphy, Laura S. Van Winkle Source Type: journals

Characterization of the expression pattern of the PRC2 core subunit Suz12 during embryonic development of Xenopus laevisEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The Polycomb repressive complex 2 is a multimeric aggregate that mediates silencing of a broad range of genes, and is associated with important biological contexts such as stem cell maintenance and cancer progression. PRC2 mainly trimethylates lysine 27 of histone H3 and is composed of three essential core subunits: EZH2, EED, and SUZ12. The Xenopus orthologs of PRC2 subunits Ezh2 and Eed have been described but Suz12 remained unidentified. Here, we report the cloning of the Xenopus Suz12, and determine its spatiotemporal expression during development. Xsuz12 transcript is provided maternally and continues to be expressed ...
Source: Developmental Dynamics - October 29, 2009 Category: Molecular Biology Authors: Issam Aldiri, Monica L. Vetter Source Type: journals

Fzd3 and Fzd6 deficiency results in a severe midbrain morphogenesis defectEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Wnt/[beta]-catenin signaling controls the proper development of the mid-/hindbrain region (MHR) and of midbrain dopaminergic (mDA) neurons, but the Frizzled (Fzd) receptors transducing these signals are still unknown. Fzd3 is expressed throughout the mouse anterior neural tube, whereas Fzd6 is restricted to the MHR. We show that the MHR is properly established and mDA neurons develop normally in Fzd6-/- mutants, but the number of mDA neurons is initially reduced and recovers at later stages in Fzd3-/- embryos. Fzd3-/-; Fzd6-/- double mutants exhibit a severe midbrain morphogenesis defect consisting of collapsed brain ventr...
Source: Developmental Dynamics - October 19, 2009 Category: Molecular Biology Authors: Sebastian Stuebner, Theresa Faus-Kessler, Thomas Fischer, Wolfgang Wurst, Nilima Prakash Source Type: journals

Sequence and expression of the zebrafish alpha-actinin gene family reveals conservation and diversification among vertebratesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We describe the temporal and spatial expression patterns of these genes through embryonic development. All zebrafish actinin genes have unique expression profiles, indicating specialization of each gene. In particular, the muscle actinins display preferential expression in different domains of axial, pharyngeal, and cranial musculature. There is no identified avian actn3 and approximately 16% of humans are null for ACTN3. Duplication of actn3 in the zebrafish indicates that variation in actn3 expression may promote physiological diversity in muscle function among vertebrates. Developmental Dynamics 238:2936-2947, 2009. © ...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Christopher K. Holterhoff, Rebecca H. Saunders, Erika E. Brito, Daniel S. Wagner Source Type: journals

Chromosomal position mediates spinal cord expression of a dbx1a enhancerEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Dbx homeodomain proteins are important for the production of multiple spinal cord cell types. To examine the regulation of Dbx genes in more detail, we have generated transgenic zebrafish in which fluorescent protein expression is driven by predicted dbx1a enhancers. We identified three areas of sequence conservation upstream of the dbx1a coding sequence and generated fluorescent reporter constructs driven by these predicted enhancer elements and the endogenous dbx1a promoter. In multiple stable insertions of a 3.5-kb enhancer fragment, we observed that there was additional reporter expression in the dorsal spinal cord not...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Suzanna L. Gribble, O. Brant Nikolaus, M. Scott Carver, Kazuyuki Hoshijima, Richard I. Dorsky Source Type: journals

Osteoblast maturation occurs in overlapping proximal-distal compartments during fin regeneration in zebrafishEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
During fin regeneration, osteoblasts must continually differentiate for outgrowth of the bony fin rays. Bone maturity increases in a distal-proximal manner, and osteoblast maturation can be detected similarly when following gene expression. We find that early markers for osteoblast differentiation are expressed in a discrete domain at the distal end of the fin, just proximal to the adjacent germinal compartment of dividing cells. Matrix genes, required at later stages developmentally, are expressed in a population of cells proximally to the early genes. A marker for mature osteoblasts is expressed in cells further proximal...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Andrew M. Brown, Shannon Fisher, M. Kathryn Iovine Source Type: journals

Homozygous disruption of the tip60 gene causes early embryonic lethalityEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Tat-interactive protein 60 (Tip60) is a member of the MYST family, proteins of which are related by an atypical histone acetyltransferase (HAT) domain. Although Tip60 has been implicated in cellular activities including DNA repair, apoptosis, and transcriptional regulation, its function during embryonic development is unknown. We ablated the Tip60 gene (Htatip) from the mouse by replacing exons 1-9 with a neomycin resistance cassette. Development and reproduction of wild-type and heterozygous animals were normal. However, homozygous ablation of the Tip60 gene caused embryolethality near the blastocyst stage of development,...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Yaofei Hu, Joseph B. Fisher, Stacy Koprowski, Donna McAllister, Min-Su Kim, John Lough Source Type: journals

Developmental expression of Smoc1 and Smoc2 suggests potential roles in fetal gonad and reproductive tract differentiationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We examined the expression and regulation of Smoc1 and Smoc2 in fetal gonad/mesonephros complexes to discover possible roles for these genes in gonad and mesonephros development. Smoc1 was upregulated at [sim]E10.75 in a center-to-poles wave in pre-Sertoli and pre-granulosa cells and its expression was greatly reduced in Wt1, Sf1, and Fog2 mutants. After E13.5, Smoc1 was downregulated in an anterior-to-posterior wave in granulosa cells but persisted in Sertoli cells, suggesting a sexually dimorphic requirement in supporting cell lineage differentiation. Smoc2 was expressed in Leydig cells, mesonephroi, and Wnt4 mutant ovar...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Dorothy E. Pazin, Kenneth H. Albrecht Source Type: journals

Comparative expression of zebrafish lats1 and lats2 and their implication in gastrulation movementsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Large tumor suppressor (Lats) is a Ser/Thr kinase, and it presents an important function in tumor suppression. lats was originally identified in Drosophila and recently in mammals. In mammals, it contains two homologues, lats1 and lats2. In the present study, lats1 and lats2 were characterized from zebrafish (Danio rerio), which is the first report of lats in a nonmammalian vertebrate. The primary structure, genomic organization, and phylogenesis of lats from different species were studied, and the results suggest that lats1 is the direct descendant of invertebrate lats, whereas lats2 is formed by genome duplication. In ze...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Chun-Hong Chen, Yong-Hua Sun, De-Sheng Pei, Zuo-Yan Zhu Source Type: journals

A developmental study of enteric neuron migration in the grasshopper using immunological probesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Motility of enteric plexus neurons in the grasshopper Locusta migratoria depends critically on the NO/cGMP signaling cascade. This is reflected in a strong NO-dependent cGMP staining in migrating enteric midgut neurons. In contrast, first cGMP immunoreactivity (cGMP-IR) in the foregut enteric ganglia was detected clearly after the main migratory processes have taken place. Thus, expression of cGMP-IR in migrating neurons is a distinct phenomenon restricted to neurons forming midgut and foregut plexus, that does not occur during convergence of neurons forming the enteric ganglia. Analysis of time lapse video microscopy of m...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Sabine Knipp, Gerd Bicker Source Type: journals

Progenitor cell maturation in the developing vertebrate retinaEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Progenitor cells in the developing retina initially divide so that each division produces two cells that divide again. Subsequently, progenitor cells change their mode of division so that one or both cells produced by a division can withdraw from the mitotic cycle and differentiate. We asked how these two progenitor cell stages differ molecularly and what controls the switch in the mode of division. We show that early preneurogenic progenitor cells express the transcription factor, Sox2, and the Notch ligand, Delta1. More mature neurogenic progenitor cells express Sox2 and the bHLH transcription factor, E2A, and not Delta1...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Hyun-Jin Yang, Amila O. Silva, Naoko Koyano-Nakagawa, Steven C. McLoon Source Type: journals

Mechanisms for split localization of Fgf10 expression in early lung developmentEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In early lung development, epithelial tubes (lung buds) intrude into mesenchyme covered with pleural cells (lung border), and form tree-like networks, by means of repeated use of morphogenetic processes: "elongation," "terminal bifurcation," and "lateral budding." When a bud is elongating, a peak of Fgf10 expression is formed in the mesenchyme near the tip; whereas when terminal bifurcation and lateral budding occur, two separate peaks are formed instead. To explain the spatial pattern of Fgf10 expression, we developed a mathematical model for the regulation of Fgf10 expression with geometrical conditions including shapes ...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Tsuyoshi Hirashima, Yoh Iwasa, Yoshihiro Morishita Source Type: journals

Functional characterization of cardiac progenitor cells and their derivatives in the embryonic heart post-chamber formationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
There is scant information on the fate of cardiac progenitor cells (CPC) in the embryonic heart after chamber specification. Here we simultaneously tracked three lineage-specific markers (Nkx2.5, MLC2v, and ANF) and confirmed that CPCs with an Nkx2.5+MLC2v-ANF- phenotype are present in the embryonic (E) day 11.5 mouse ventricular myocardium. We demonstrated that these CPCs could give rise to working cardiomyocytes and conduction system cells. Using a two-photon imaging analysis, we found that the majority of CPCs are not capable of developing Ca2+ transients in response to [beta]-adrenergic receptor stimulation. In contras...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Nichole M. McMullen, Feixiong Zhang, Adam Hotchkiss, Frederic Bretzner, Jennifer M. Wilson, Hong Ma, Karim Wafa, Robert M. Brownstone, Kishore B.S. Pasumarthi Source Type: journals

Embryogenesis and ossification of Emydura subglobosa (Testudines, Pleurodira, Chelidae) and patterns of turtle developmentEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Using the Standard Event System (SES) to study patterns of vertebrate development, we describe a series of 17 embryos of the pleurodire turtle Emydura subglobosa. Based on a sequence heterochrony analysis including 23 tetrapod taxa, we identified autapomorphic developmental shifts that characterise Testudines, Cryptodira, and Pleurodira. The main results are that Testudines are characterised by an autapomorphic late neck development, whereas pleurodires and cryptodires show a different developmental timing of the mandibular process. Additionally, we described the ossification pattern of E. subglobosa and compared the data ...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Ingmar Werneburg, Jasmina Hugi, Johannes Müller, Marcelo R. Sánchez-Villagra Source Type: journals

Role of VEGF and tissue hypoxia in patterning of neural and vascular cells recruited to the embryonic heartEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We hypothesized that oxygen gradients and hypoxia-responsive signaling may play a role in the patterning of neural or vascular cells recruited to the developing heart. Endothelial progenitor and neural cells are recruited to and form branched structures adjacent to the relatively hypoxic outflow tract (OFT) myocardium from stages 27-32 (ED6.5-7.5) of chick development. As determined by whole mount confocal microscopy, the neural and vascular structures were not anatomically associated. Adenoviral delivery of a VEGF trap dramatically affected the remodeling of the vascular plexus into a coronary tree while neuronal branchin...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Hongbin Liu, Qiwei Yang, Krishnan Radhakrishnan, Dedra E. Whitfield, Camille L. M. Everhart, Patricia Parsons-Wingerter, Steven A. Fisher Source Type: journals

Foxg1 is required for proper separation and formation of sensory cristae during inner ear developmentEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The vestibular portion of the inner ear, the three semicircular canals and their sensory cristae, is responsible for detecting angular head movements. It was proposed that sensory cristae induce formation of their non-sensory components, the semicircular canals. Here, we analyzed the inner ears of Foxg1-/- mouse mutants, which display vestibular defects that are in conflict with the above model. In Foxg1-/- ears, the lateral canal is present without the lateral ampulla, which houses the lateral crista. Our gene expression analyses indicate that at the time when canal specification is thought to occur, the prospective later...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Chan Ho Hwang, Antonio Simeone, Eseng Lai, Doris K. Wu Source Type: journals

DD ArtPixEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
No abstract. (Source: Developmental Dynamics)
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Source Type: journals

Highlights in DDEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
No abstract. (Source: Developmental Dynamics)
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Julie C. Kiefer Source Type: journals

Identification of novel genes involved in the development of the sword and gonopodium in swordtail fishEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
COVER PHOTOGRAPH: Bony fin rays of the gonopodium, an intromittent organ, of the male swordtail fish, Xiphophorus helleri. Distal skeletal elements are differentiated into hook-like structures that facilitate efficient sperm transfer during internal fertilization. From Offen et al., Developmental Dynamics 238:1674-1687, 2009. © 2009 Wiley-Liss, Inc. (Source: Developmental Dynamics)
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Nils Offen, Axel Meyer, Gerrit Begemann Source Type: journals

Xenopus axin-related protein: A link between its centrosomal localization and function in the Wnt/[beta]-catenin pathwayEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The Wnt/[beta]-catenin signaling pathway regulates cell proliferation and cell fate determination in multiple systems. However, the subcellular localization of Wnt pathway components and the significance of this localization for the pathway regulation have not been extensively analyzed. Here we report that Xenopus Axin-related protein (XARP), a component of the [beta]-catenin destruction complex, is localized to the centrosome. This localization of XARP requires the presence of the DIX domain and an adjacent region. Since other components of the Wnt pathway have also been shown to associate with the centrosome, we tested a...
Source: Developmental Dynamics - October 18, 2009 Category: Molecular Biology Authors: Evguenia M. Alexandrova, Sergei Y. Sokol Source Type: journals

Different timings of dicer deletion affect neurogenesis and gliogenesis in the developing mouse central nervous systemEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
MicroRNAs, processed by the RNAase III enzyme Dicer, are [sim]22 nucleotide endogenous noncoding small RNAs. The function of Dicer in the mouse central nervous system (CNS) development is not well understood. Here, we show that specifically deleting Dicer expression in the CNS and in the cerebral cortex using two Cre lines results in reduced progenitor numbers, abnormal neuronal differentiation, and thinner cortical wall. Incomplete Dicer deletion during early embryonic stages contributes to normal development of early-born neurons in the cortex and motor neurons in the spinal cord. However, at late embryonic stages when D...
Source: Developmental Dynamics - October 5, 2009 Category: Molecular Biology Authors: Yoko Kawase-Koga, Gaizka Otaegi, Tao Sun Source Type: journals

Patterns of Wnt pathway activity in the mouse incisor indicate absence of Wnt/[beta]-catenin signaling in the epithelial stem cellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The Wnt pathway is crucial for tooth development as shown by dental defects caused by impaired Wnt signaling in mouse and human. We investigated Wnt signaling in continuously growing mouse incisors focusing on epithelial stem cells. Ten Wnt ligands were expressed both in the dental epithelium and mesenchyme, and were associated mainly with odontoblast and ameloblast differentiation. Wnt/[beta]-catenin activity was detected in mesenchyme in BATgal and TOPgal reporter mice while Axin2, also a reporter of Wnt/[beta]-catenin signaling, was expressed additionally in the epithelium. Axin2 was, however, excluded from the epitheli...
Source: Developmental Dynamics - October 4, 2009 Category: Molecular Biology Authors: Marika Suomalainen, Irma Thesleff Source Type: journals

CAZIP, a novel protein expressed in the developing heart and nervous systemEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Recently, we have performed a whole genome micro-array analysis on human embryonic stem cells differentiating toward cardiomyocytes, which resulted in the identification of novel genes that were highly up-regulated during differentiation. Here, we describe one of these novel genes annotated as KIAA0774. The predicted protein contains a leucine-zipper domain at the C-terminus and has at least two isoforms (358 and 1354 amino acids). Whole-mount in situ hybridization confirmed that the mRNA of both the mouse and chicken orthologs of KIAA0774 is expressed during early cardiac development. Hence, we named this protein CAZIP (c...
Source: Developmental Dynamics - October 4, 2009 Category: Molecular Biology Authors: Leonie Du Puy, Abdelaziz Beqqali, Jantine Monshouwer-Kloots, Henk P. Haagsman, Bernard A.J. Roelen, Robert Passier Source Type: journals

Genetic interaction between Lrp6 and Wnt5a during mouse developmentEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Lrp6 is generally described as a receptor required for signal transduction in the Wnt/[beta]-catenin pathway. Wnt5a, however, is a Wnt ligand that usually does not activate Wnt/[beta]-catenin but rather activates noncanonical Wnt signaling. We have previously shown that Lrp6 can inhibit noncanonical Wnt5a/Wnt11 signaling and that Lrp5/6 loss-of-function produces noncanonical gain-of function defects, which can be rescued by loss of Wnt5a. Here, we describe other phenotypes found in Wnt5a/Lrp6 compound mutant mice, including a worsening of individual Wnt5a or Lrp6 loss of function phenotypes. Lrp6 haploinsufficiency in a Wn...
Source: Developmental Dynamics - September 30, 2009 Category: Molecular Biology Authors: Emma Andersson, Lenka Bryjova, Kristin Biris, Terry P. Yamaguchi, Ernest Arenas, Vít[ecaron]zslav Bryja Source Type: journals

Identification of starmaker-like in medaka as a putative target gene of Pax2 in the otic vesicleEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Otoliths in bony fishes are involved in the function of the ear in the senses of balance and hearing. In a large-scale random in situ hybridization screen of genes expressed in the medaka developing ear, we identified starmaker-like (stm-l) gene, a novel homologue of zebrafish starmaker and human dentine sialo-phosphoprotein (dspp) gene. Despite the absence of sequence similarity between these genes, here we describe their similar genomic structure and expression patterns hinting for a conserved function. In medaka fry, stm-l is expressed in various organs such as otoliths, teeth, gills, and kidney. Additionally, our resul...
Source: Developmental Dynamics - September 29, 2009 Category: Molecular Biology Authors: Baubak Bajoghli, Mirana Ramialison, Narges Aghaallaei, Thomas Czerny, Joachim Wittbrodt Source Type: journals