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 'Developmental Dynamics' source. Thu, 09 Feb 2012 16:56:41 +0100 http://www.medworm.com/index.php?rid=5656480&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23755 Conclusions:The Wnt/β‐catenin signal coordinates expression of multiple epithelial signals and has stage‐specific asymmetric functions during mammalian upper and lower jaw development. In addition, these findings suggest that evolutionary changes of the canonical Wnt/β‐catenin signaling pathway may lead to innovation of jaws. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5656480 Thu, 02 Feb 2012 05:00:00 +0100 5656480 http://www.medworm.com/index.php?rid=5656479&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23754 AbstractNotch signaling is active in mouse cochlear prosensory progenitors but declines in differentiating sensory hair cells (HCs). Overactivation of the Notch1 intracellular domain (NICD) in progenitors blocks HC fate commitment and/or differentiation. However, it is not known whether reactivation of NICD in differentiating HCs also interrupts their developmental program and reactivates its downstream targets. By analyzing Atoh1CreER+; Rosa26‐NICDloxp/+ or Atoh1CreER+; Rosa26‐NICDloxp/+; RBP‐Jloxp/loxp mice, we demonstrated that ectopic NICD in differentiating HCs caused reactivation of Sox2 and Prox1 in an RBP‐J–dependent manner. Interestingly, Prox1 reactivation was exclusive to outer HCs (OHCs). In addition, lineage tracing analysis of Prox1CreER/+; Rosa26‐EYFPloxp/+ and P... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5656479 Thu, 02 Feb 2012 05:00:00 +0100 5656479 http://www.medworm.com/index.php?rid=5673935&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23756 Conclusions.We conclude that a slight and transient deregulation of Hoxd13 expression can readily affect the relative lengths of limb segments and that all posterior Hoxd genes likely contribute to the final limb morphology. We discuss the difficulty to clearly assess the functional share of individual genes within such a gene family, where closely located neighbors, coding for homologous proteins, are regulated by a unique circuitry and all contribute to shape the distal parts of our appendages. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5673935 Wed, 01 Feb 2012 05:00:00 +0100 5673935 http://www.medworm.com/index.php?rid=5656481&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23750 AbstractDeterioration of the intervertebral discs is an unfortunate consequence of aging. The intervertebral disc in mammals is composed of three parts: a jelly‐like center called the nucleus pulposus, the cartilaginous annulus fibrosus and anterior and posterior endplates that attach the discs to vertebrae. In order to understand the origin of the disc, we have investigated the intervertebral region of chickens. Surprisingly, our comparison of mouse and chicken discs revealed that chicken discs lack nuclei pulposi. In addition, the notochord, which in mice forms nuclei pulposi, was found to persist as a rod‐like structure and express Shh throughout chicken embryogenesis. Our fate mapping data indicates that cells originating from the rostral half of each somite are responsible for for... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5656481 Wed, 01 Feb 2012 05:00:00 +0100 5656481 http://www.medworm.com/index.php?rid=5656478&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23753 ConclusionsPaladin, a novel putative phosphatase, displays a dynamic expression pattern in the vasculature. During embryonic stages it is broadly expressed in endothelial cells, while in the adult it is selectively expressed in arterial smooth muscle cells. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5656478 Wed, 01 Feb 2012 05:00:00 +0100 5656478 http://www.medworm.com/index.php?rid=5635418&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23748 AbstractEndogenous retinoic acid plays critical roles in normal vertebrate development, but can be teratogenic in excess. In mice, additional retinoic acid is administered by oral gavage or intraperitoneal injection. Here we evaluate a novel non‐invasive system for administering retinoic acid via chocolate/sugar pellets. We use this delivery system to examine the role of retinoic acid in regulating the expression of the fibroblast growth factor Fgf3, and find that the timing of retinoic acid treatment is critical for its effects on Fgf3 expression. Administration of increasing amounts of retinoic acid at 7.75dpc leads to dose‐dependent downregulation of Fgf3 in the otocyst and changes in spatial expression in the hindbrain. Detailed analysis of the developing inner ear also reveals a l... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5635418 Fri, 27 Jan 2012 21:41:50 +0100 5635418 http://www.medworm.com/index.php?rid=5635419&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23749 In this study we examined Roundabout signaling in the Drosophila embryonic hindgut. Slit and its receptors Roundabout (Robo) and Roundabout 2 (Robo2) localize to discrete regions in the hindgut epithelium and surrounding visceral mesoderm. Loss of robo, robo2 or slit did not disrupt overall hindgut patterning. However slit and robo mutants showed a decrease in microvillus length on the boundary cells of the hindgut epithelium. Rescue and overexpression analysis revealed that robo is specifically required in the visceral mesoderm for correct microvillus length in the underlying hindgut epithelium. Expression of robo in the visceral mesoderm of robo mutant embryos restored normal microvillus length, while overexpression of robo resulted in an increase in microvillus length. Microvillus lengt... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5635419 Wed, 25 Jan 2012 05:00:00 +0100 5635419 http://www.medworm.com/index.php?rid=5624799&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23724 Conclusions: The anti‐Rec1 antibody antibody developed using Drosophila pro‐resilin as antigen is cross‐reactive and is useful for detection of resilin in diverse insects. For the first time, resilin expression has been detected during embryogenesis, revealing segmental patches of resilin in the developing epidermis of Drosophila. Developmental Dynamics 241:333–339, 2012. © 2012 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5624799 Tue, 24 Jan 2012 22:03:42 +0100 5624799 http://www.medworm.com/index.php?rid=5624798&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23733 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5624798 Tue, 24 Jan 2012 22:03:29 +0100 5624798 http://www.medworm.com/index.php?rid=5624797&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23704 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5624797 Tue, 24 Jan 2012 22:03:28 +0100 5624797 http://www.medworm.com/index.php?rid=5624796&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23732 AbstractNematostella 3 heads: Induction of canonical Wnt signaling causes regenerating Nematostella to form ectopic oral poles at sites of injury. From Trevino et al., Developmental Dynamics 240:2673–2679, 2011. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5624796 Tue, 24 Jan 2012 22:03:26 +0100 5624796 http://www.medworm.com/index.php?rid=5624792&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23745 Conclusions:Our findings indicate that neogenin regulates SHH signaling in the limb bud to achieve proper digit patterning. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5624792 Tue, 24 Jan 2012 22:03:03 +0100 5624792 http://www.medworm.com/index.php?rid=5624794&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23747 Conclusions:Here we report our success with in vivo microelectroporations of E1 embryos as young as Hamburger‐Hamilton Stage 4 (HH4). We provide evidence that such electroporations can be varied in size and can be spatially targeted. They cause minimal disruption of tissue size, 3‐dimensional morphology, cell survival, proliferation and cellfate specification. Our paradigm is easily adapted to a variety of experimental conditions since it does not depend upon the presence of a lumen to enclose the DNA solution during electroporation. It is thus compatible with the in vivo examination of E1 morphogenetic events (e.g., neural tube closure) where preservation of 3‐dimensional morphology is critical. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc. (Source: Developmental Dyn... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5624794 Mon, 23 Jan 2012 05:00:00 +0100 5624794 http://www.medworm.com/index.php?rid=5624793&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23746 AbstractL‐type calcium channels (LTCC) regulate calcium entry into cardiomyocytes. CACNB2 (β2) LTCC auxiliary subunits traffic the pore‐forming CACNA subunit to the membrane and modulate channel kinetics. β2 is a Membrane Associated Guanylate Kinase (MAGUK) protein. A major role of MAGUK proteins is to scaffold cellular junctions and multi‐protein complexes. To investigate developmental functions for β2.1, we depleted it in zebrafish using morpholinos. β2.1‐depleted embryos developed compromised cardiac function by 48 hours post‐fertilization, which was ultimately lethal. β2.1 contractility defects were mimicked by pharmacological depression of LTCC, and rescued by LTCC stimulation, suggesting β2.1 phenotypes are at least in part LTCC‐dependent. Morphological studies indi... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5624793 Mon, 23 Jan 2012 05:00:00 +0100 5624793 http://www.medworm.com/index.php?rid=5656483&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23743 AbstractVEGF165b is an anti‐angiogenic form of VEGF165 produced by alternative splicing. The localization of pro‐angiogenic VEGF165 and anti‐angiogenic VEGF165b was investigated during development of the vasculatures in fetal human eyes from 7 to 21 weeks gestation (WG). The fetal vasculature of vitreous, which includes tunica vasculosa lentis (TVL), had moderate VEGF165 immunoreactivity at 7WG and very little VEGF165b. Both forms were elevated at 12WG. VEGF165 then decreased around 17WG when the TVL regresses but VEGF165b remained elevated. In choroid, VEGF165 was present in forming choriocapillaris (CC) and retinal pigment epithelium (RPE) at 7WG while VEGF165b was present in CC and mesenchymal precursors within the choroidal stroma. By 21WG, both forms were elevated in RPE and cho... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5656483 Thu, 19 Jan 2012 05:00:00 +0100 5656483 http://www.medworm.com/index.php?rid=5617029&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23744 In conclusion, multivariate morphometric analysis provides a powerful tool to quantify and assess urinary tract development. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5617029 Thu, 19 Jan 2012 05:00:00 +0100 5617029 http://www.medworm.com/index.php?rid=5656482&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23734 Conclusions: These results support a model whereby HLH‐8/HLH‐8 homodimers function in M lineage patterning and enteric muscles and HLH‐8/HLH‐2 heterodimers function in the M‐derived vulval muscles. Interestingly, the different dimers function in the same M lineage cells and the switch in dimer function coincides with vulval muscle differentiation. The use of distinct Twist dimers is evolutionarily conserved, and C. elegans provides a paradigm for future dissection of differential promoter regulation by these dimers at a single cell resolution. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5656482 Fri, 13 Jan 2012 05:00:00 +0100 5656482 http://www.medworm.com/index.php?rid=5593063&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23742 Conclusion:All four WASP family members show specific expression patterns, some of which reflect their previously known roles and others revealing new potential functions. The monoclonal antibodies developed offer valuable new tools to investigate how WASP family proteins regulate actin cytoskeleton dynamics. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5593063 Fri, 13 Jan 2012 05:00:00 +0100 5593063 http://www.medworm.com/index.php?rid=5593061&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23740 This study analyzed the expression of several claudins during mouse pancreas organogenesis and in pancreatic intraepithelial neoplasias of mouse and human origin. Our results underscored a distinctive, dynamic distribution of certain claudins in both the developing pancreas and the pancreatic epithelium undergoing neoplastic transformation. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5593061 Fri, 13 Jan 2012 05:00:00 +0100 5593061 http://www.medworm.com/index.php?rid=5593060&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23739 AbstractDuring vertebrate lens development the lens placode in the embryonic ectoderm invaginates into a lens vesicle, which then separates from the surface epithelium, followed by two waves of fiber cell differentiation. In the mouse, multiple labs have shown that Jag1‐Notch signaling is critically required during the second wave of lens fiber cell formation. However, Notch signaling appears to play no obvious role during lens induction or morphogenesis, although multiple pathway genes are expressed at these earlier stages. Here we explored functions for Notch signaling specifically during early lens development, by using the early‐acting AP2α‐Cre driver to delete Jag1 or Rbpj. We found that Jag1 and Rbpj are not required during lens induction, but are necessary for proper lens ves... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5593060 Fri, 13 Jan 2012 05:00:00 +0100 5593060 http://www.medworm.com/index.php?rid=5593059&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23738 ConclusionsWe conclude that lilliputian is part of the genetic program that regulates the expression of proneural genes in the developing retina. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5593059 Fri, 13 Jan 2012 05:00:00 +0100 5593059 http://www.medworm.com/index.php?rid=5593058&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23737 We report here that Astacin‐like (ASTL) is strongly expressed in mouse and chicken embryonic stem (ES) cells and exhibits a very dynamic expression pattern during embryogenesis and organogenesis, mostly in remodelled epithelia. Consistent with its expression in ES cells, chick ASTL is detected in vivo in the pluripotent cells of the epiblast and then disappears from the newly induced neural plate. ASTL expression remains at the junction of non neural and neural ectoderm, just before neural tube closure. At later stages, chick ASTL is detected in the ventral epidermis before ventral closure, in the intermediate mesoderm, in the gonads and in the forming nephric duct and tubules of the mesonephros and metanephros. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5593058 Fri, 13 Jan 2012 05:00:00 +0100 5593058 http://www.medworm.com/index.php?rid=5593057&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23736 Conclusions:Our analysis of ear development provides new insights into ear development, enables unique perspectives into the complex development of the ear, and allows for the first full quantification of volumetric and linear aspects of ear growth. Our data provide the framework for future analysis of mutant phenotypes that are currently under‐appreciated using only two dimensional renderings. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5593057 Fri, 13 Jan 2012 05:00:00 +0100 5593057 http://www.medworm.com/index.php?rid=5593056&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23735 Conclusions:TEG‐1 functions as a splicing factor and acts to regulate the proliferation vs. meiosis decision. The interaction of TEG‐1 CD2BP2 with UAF‐1 U2AF65, combined with its previously described function in U4/U6.U5 tri‐snRNP, suggests that TEG‐1 CD2BP2 functions in two distinct locations in the splicing cascade. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5593056 Fri, 13 Jan 2012 05:00:00 +0100 5593056 http://www.medworm.com/index.php?rid=5624795&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23727 Conclusions: Doppler OCT is well suited for rapid noninvasive screening for functional changes in avian embryos under near physiological conditions. Analysis of the accessible vitelline artery sensitively reflected changes in heart function and can be used for rapid screening. Acute hypoxia caused rapid hemodynamic changes in looping hearts and may be a concern for increased CHD risk. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5624795 Tue, 03 Jan 2012 05:00:00 +0100 5624795 http://www.medworm.com/index.php?rid=5568858&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23731 This study provides a series of newly identified RA effector genes for inner ear development downstream of mesenchymal Tbx1 that may contribute to the inner ear phenotype observed in Tbx1 loss of function mouse models. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5568858 Tue, 03 Jan 2012 05:00:00 +0100 5568858 http://www.medworm.com/index.php?rid=5568857&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23730 Conclusions:Our studies suggest that p55 is not crucial for PRC2‐mediated gene silencing in vivo, and the vital function of p55 is probably not dependent on its interaction with histone H4. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5568857 Tue, 03 Jan 2012 05:00:00 +0100 5568857 http://www.medworm.com/index.php?rid=5568856&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23729 Conclusions:Cdh11 expression in the developing visual system and Cdh11 loss‐of‐function phenotype illustrates the critical role for differential cadherin activity in visual system differentiation and organization. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5568856 Tue, 03 Jan 2012 05:00:00 +0100 5568856 http://www.medworm.com/index.php?rid=5568855&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23728 AbstractAlthough urodela amphibians completely regenerate amputated limbs, the potency of limb regeneration in mammalians is very low. In mice and humans, a digit tip regenerates, but no regeneration beyond the digit joint occurs.In this paper, we describe the induction of bone formation by BMPs in the forearm, a more proximal region, of neonatal mice. Distal halves of the radius and ulna were removed from limbs amputated at the wrist level in advance, and gelatin rods containing BMPs were grafted in the space of the forearm. BMP‐7 and BMP‐2 were effective.The induction of bone formation depended on the amount of BMP‐7 in grafted gelatin gels. BMP‐7 at over 320 ng/limb induced long bones within 10 days.Cartilage formation was always observed before the bone formation as in the case... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5568855 Tue, 03 Jan 2012 05:00:00 +0100 5568855 http://www.medworm.com/index.php?rid=5617028&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23743 AbstractVEGF165b is an antiangiogenic form of VEGF165 produced by alternative splicing. The localization of proangiogenic VEGF165 and antiangiogenic VEGF165b was investigated during development of the vasculatures in fetal human eyes from 7 to 21 weeks gestation (WG). The fetal vasculature of vitreous, which includes tunica vasculosa lentis (TVL), had moderate VEGF165 immunoreactivity at 7WG and very little VEGF165b. Both forms were elevated at 12WG. VEGF165 then decreased around 17WG when the TVL regresses but VEGF165b remained elevated. In choroid, VEGF165 was present in forming choriocapillaris (CC) and retinal pigment epithelium (RPE) at 7WG while VEGF165b was present in CC and mesenchymal precursors within the choroidal stroma. By 21WG, both forms were elevated in RPE and choroidal bl... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5617028 Sun, 01 Jan 2012 05:00:00 +0100 5617028 http://www.medworm.com/index.php?rid=5593055&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23734 Conclusions:These results support a model whereby HLH‐8/HLH‐8 homodimers function in M lineage patterning and enteric muscles and HLH‐8/HLH‐2 heterodimers function in the M‐derived vulval muscles. Interestingly, the different dimers function in the same M lineage cells and the switch in dimer function coincides with vulval muscle differentiation. The use of distinct Twist dimers is evolutionarily conserved, and C. elegans provides a paradigm for future dissection of differential promoter regulation by these dimers at a single cell resolution. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5593055 Sun, 01 Jan 2012 05:00:00 +0100 5593055 http://www.medworm.com/index.php?rid=5568854&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23727 Conclusions:Doppler OCT is well suited for rapid non‐invasive screening for functional changes in avian embryos under near physiological conditions. Analysis of the accessible vitelline artery sensitively reflected changes in heart function and can be used for rapid screening. Acute hypoxia caused rapid hemodynamic changes in looping hearts and may be a concern for increased CHD risk. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5568854 Sun, 01 Jan 2012 05:00:00 +0100 5568854 http://www.medworm.com/index.php?rid=5520382&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23705 Conclusion: Loss of miR‐8 increased the sensitivity of Drosophila to higher temperatures for both pigmentation patterning and the ability to eclose. Together, these data suggest that miR‐8 acts as a buffer to stabilize gene expression patterns in the midst of environmental variation. Developmental Dynamics 241:161–168, 2012. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520382 Tue, 20 Dec 2011 09:36:18 +0100 5520382 http://www.medworm.com/index.php?rid=5520381&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23707 AbstractSince the discovery of a single white‐eyed male in a population of red eyed flies over 100 years ago (Morgan, 1910), the compound eye of the fruit fly, Drosophila melanogaster, has been a favorite experimental system for identifying genes that regulate various aspects of development. For example, a fair amount of what we know today about enzymatic pathways and vesicular transport is due to the discovery and subsequent characterization of eye color mutants such as white. Likewise, our present day understanding of organogenesis has been aided considerably by studies of mutations, such as eyeless, that either reduce or eliminate the compound eyes. But by far the phenotype that has provided levers into the greatest number of experimental fields has been the humble “rough” eye. Th... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520381 Tue, 20 Dec 2011 09:36:15 +0100 5520381 http://www.medworm.com/index.php?rid=5520379&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23712 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520379 Tue, 20 Dec 2011 09:36:00 +0100 5520379 http://www.medworm.com/index.php?rid=5520378&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23709 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520378 Tue, 20 Dec 2011 09:35:59 +0100 5520378 http://www.medworm.com/index.php?rid=5520377&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22777 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520377 Tue, 20 Dec 2011 09:35:58 +0100 5520377 http://www.medworm.com/index.php?rid=5520376&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23708 AbstractOverexpression of human GATA4 in the Drosophila eyes through the GMR‐GAL4 driver. All flies show narrow eyes. The original photograph has been duplicated for esthetic purposes to create 6 panels. From Amodio et al., Developmental Dynamics 241:205‐213, 2012. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520376 Tue, 20 Dec 2011 09:35:57 +0100 5520376 http://www.medworm.com/index.php?rid=5520368&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23725 AbstractThe single spanning transmembrane amyloid precursor protein (APP) and its proteolytic product, amyloid‐beta (Aβ) peptide, have been intensely studied due to their role in the pathogenesis of Alzheimer's disease. However, the biological role of the secreted ectodomain of APP, which is also generated by proteolytic cleavage, is less well understood. Here, we report Tol2 RFP transposon gene trap integrations in the zebrafish amyloid precursor protein a (appa) and amyloid precursor‐like protein 2 (aplp2) genes. The transposon integrations are predicted to disrupt the appa and aplp2 genes to primarily produce secreted ectodomains of the corresponding proteins that are fused to RFP. Our results indicate the Appa‐RFP and Aplp2 fusion proteins are likely secreted from the central ne... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520368 Tue, 20 Dec 2011 09:35:31 +0100 5520368 http://www.medworm.com/index.php?rid=5520369&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23726 AbstractThe Frontonasal Ectodermal Zone (FEZ) is a signaling center in the face that expresses Sonic hedgehog (Shh) and regulates patterned growth of the upper jaw. Blocking SHH in the forebrain blocks Shh expression in the FEZ and creates malformations resembling holoprosencephaly (HPE), while inhibition of BMP signaling in the mesenchyme blocks FEZ formation and causes similar dysmorphology. Thus, the brain could regulate FEZ formation by SHH or BMP signaling, and if so, activating one of these pathways in the face might alleviate the effects of repression of SHH in the brain. We blocked SHH signaling in the brain while adding SHH or BMP between the neural and facial ectoderm of the frontonasal process. When applied early, SHH restored Shh expression in the FEZ and significantly improved... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520369 Mon, 19 Dec 2011 05:00:00 +0100 5520369 http://www.medworm.com/index.php?rid=5520374&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23721 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520374 Fri, 16 Dec 2011 05:00:00 +0100 5520374 http://www.medworm.com/index.php?rid=5520373&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23720 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520373 Fri, 16 Dec 2011 05:00:00 +0100 5520373 http://www.medworm.com/index.php?rid=5520372&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23719 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520372 Fri, 16 Dec 2011 05:00:00 +0100 5520372 http://www.medworm.com/index.php?rid=5520370&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23717 AbstractThe function of Notch signaling in murine neural crest‐derived cell lineages in vivo was examined. Conditional gain (Wnt1Cre;RosaNotch) or loss (Wnt1Cre;RBP‐Jf/f) of Notch signaling in neural crest cells (NCCs) in vivo results in craniofacial, cardiac, and trunk abnormalities. Severe craniofacial malformations are apparent in Wnt1Cre;RosaNotch embryos, while less severe skull abnormalities are evident in Wnt1Cre;RBP‐Jf/f mice. Deficient cardiac neural crest migration, resulting in cardiac outflow tract malformations, occurs with increased or decreased Notch signaling in NCCs. Smooth muscle cell differentiation also is impaired in pharyngeal NCC derivatives in both Wnt1Cre;RosaNotch and Wnt1Cre;RBP‐Jf/f embryos. Neurogenesis is absent and gliogenesis is increased in the dors... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520370 Thu, 15 Dec 2011 05:00:00 +0100 5520370 http://www.medworm.com/index.php?rid=5501102&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23723 AbstractDuring Xenopus laevis metamorphosis, Sonic hedgehog (Shh) is directly induced by thyroid hormone (TH) at the transcription level as one of the earliest events in intestinal remodeling. However, the regulation of other components of this signaling pathway remains to be analyzed. Here, we analyzed the spatiotemporal expression of Patched (Ptc)‐1, Smoothened (Smo), Gli1, Gli2 and Gli3 during natural and TH‐induced intestinal remodeling. We show that all of the genes examined are transiently up‐regulated in the mesenchymal tissues during intestinal metamorphosis. Interestingly, in the presence of protein synthesis inhibitors, Gli2 but not the others was induced by TH, suggesting that Gli2 is a direct TH response gene, while the others are likely indirect ones. Furthermore, we dem... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5501102 Mon, 12 Dec 2011 05:00:00 +0100 5501102 http://www.medworm.com/index.php?rid=5520375&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23711 AbstractDuring gastrulation, an embryo acquires the three primordial germ layers that will give rise to all of the tissues in the body. In amniote embryos, this process occurs by means of an epithelial to mesenchymal transition (EMT) of epiblast cells at the primitive streak. Although the primitive streak is vital to development, many aspects of how it forms and functions remain poorly understood. Using live imaging and immunohistochemistry, we have shown that the murine primitive streak arises in situ by progressive initiation of EMT beginning in the posterior epiblast, without large‐scale movement or convergence and extension of epiblast cells. Loss of basal lamina (BL) is the first step of this EMT, and is strictly correlated with ingression of nascent mesoderm. This is the first desc... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520375 Tue, 06 Dec 2011 05:00:00 +0100 5520375 http://www.medworm.com/index.php?rid=5520371&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23716 AbstractTrabeculation is an integral component of cardiac ventricular morphogenesis, involving the hyaluronan binding proteoglycan, versican, and the versican cleaving matrix metalloproteinase, ADAMTS1. Fibulin‐1 is a versican and ADAMTS1‐binding extracellular matrix protein required for ventricular morphogenesis. We show that fibulin‐1 is a cofactor for ADAMTS1‐dependent in vitro cleavage of versican V1, yielding a 70‐kDa amino‐terminal fragment. Furthermore, fibulin‐1‐deficiency in mice was found to cause a significant reduction (>90%) in ventricular levels of the 70‐kDa versican V1 cleavage product and a two‐fold increase in trabecular cardiomyocyte proliferation. Decreased versican V1 cleavage and augmented trabecular cardiomyocyte proliferation in fibulin‐1 nu... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5520371 Tue, 06 Dec 2011 05:00:00 +0100 5520371 http://www.medworm.com/index.php?rid=5483102&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23716 AbstractTrabeculation is an integral component of cardiac ventricular morphogenesis, involving the hyaluronan binding proteoglycan, versican, and the versican cleaving matrix metalloproteinase, ADAMTS1. Fibulin‐1 is a versican and ADAMTS1‐binding extracellular matrix protein required for ventricular morphogenesis. We show that fibulin‐1 is a cofactor for ADAMTS1‐dependent in vitro cleavage of versican V1, yielding a 70‐kDa amino‐terminal fragment. Furthermore, fibulin‐1‐deficiency in mice was found to cause a significant reduction (>90%) in ventricular levels of the 70‐kDa versican V1 cleavage product and a 2‐fold increase in trabecular cardiomyocyte proliferation. Decreased versican V1 cleavage and augmented trabecular cardiomyocyte proliferation in fibulin‐1 null... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5483102 Tue, 06 Dec 2011 05:00:00 +0100 5483102 http://www.medworm.com/index.php?rid=5483101&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23715 AbstractHyaluronan is a crucial glycosaminoglycan of the vertebrate embryonic extracellular matrix able to influence cell behaviour, both by assembling the pericellular matrices and by activating signal transducing receptors such as CD44. We showed that the hyaluronan synthases, Has1 and Has2, and CD44 display a dynamic expression pattern during cranial neural crest cells (NCC) development. By knocking down Has1 and Has2 gene functions, we revealed that hyaluronan synthesized by Has1 and Has2 is necessary for the proper development of the visceral skeleton. The data suggest that hyaluronan helps to maintain the active migratory behaviour of cranial NCC, and that its presence around pre‐chondrogenic NCC is crucial for their survival. CD44 knock down also suggests that the role of hyaluron... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5483101 Tue, 06 Dec 2011 05:00:00 +0100 5483101 http://www.medworm.com/index.php?rid=5483100&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23714 AbstractThe cardiac progenitor cells for the outflow tract (OFT) reside in the visceral mesoderm and mesodermal core of the pharyngeal region, which are defined as the secondary and anterior heart fields (SHF and AHF), respectively. Using chick embryos, we injected fluorescent‐dye into the SHF or AHF at stage 14, and the destinations of the labeled cells were examined at stage 31. Labeled cells from the right SHF were found in the myocardium on the left dorsal side of the OFT, and cells from the left SHF were detected on the right ventral side of the OFT. Labeled cells from the right and left AHF migrated to regions of the ventral wall of the OFT close to the aortic and pulmonary valves, respectively. These observations indicate that myocardial progenitors from the SHF and AHF contribute... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5483100 Tue, 06 Dec 2011 05:00:00 +0100 5483100 http://www.medworm.com/index.php?rid=5483099&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23713 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5483099 Tue, 06 Dec 2011 05:00:00 +0100 5483099 http://www.medworm.com/index.php?rid=5483098&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23711 AbstractDuring gastrulation, an embryo acquires the three primordial germ layers that will give rise to all of the tissues in the body. In amniote embryos, this process occurs via an epithelial to mesenchymal transition (EMT) of epiblast cells at the primitive streak. Although the primitive streak is vital to development, many aspects of how it forms and functions remain poorly understood. Using live imaging and immunohistochemistry, we have shown that the murine primitive streak arises in situ by progressive initiation of EMT beginning in the posterior epiblast, without large‐scale movement or convergence and extension of epiblast cells. Loss of basal lamina (BL) is the first step of this EMT, and is strictly correlated with ingression of nascent mesoderm. This is the first description ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5483098 Tue, 06 Dec 2011 05:00:00 +0100 5483098 http://www.medworm.com/index.php?rid=5483097&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23710 This study characterizes the expression of Tbx2 subfamily genes during development of the reproductive system. We show that these genes are expressed in both the internal and external reproductive systems. Tbx2 is expressed in gonads and genital ducts – the Wolffian and Müllerian ducts – while Tbx3 is only expressed in genital ducts. Tbx4 is expressed in embryonic and postnatal germ cells. All four genes are expressed in mesenchyme in external genitalia, with Tbx3 and Tbx5 expression in the epithelium as well. This study lays the foundation for investigation of functional requirements for Tbx2 subfamily genes in development of the mammalian reproductive system. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5483097 Tue, 06 Dec 2011 05:00:00 +0100 5483097 http://www.medworm.com/index.php?rid=5501101&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23722 Conclusions:Overall these data suggest the involvement of NO during cuttlefish development in different fundamental processes, such as differentiation of neural and non‐neural structures, ciliary beating, sensory cell maintaining and organ functioning. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5501101 Thu, 01 Dec 2011 05:00:00 +0100 5501101 http://www.medworm.com/index.php?rid=5492625&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23718 In this study we found that olig2 function is required for facial motor neurons to complete their caudal migration into r6 and r7 and form stereotypical clusters. Additionally, embryos that lack mafba function, in which facial motor neurons also fail to complete caudal migration, lack olig2 expression in r5 and r6. Our data raise the possibility that cells expressing olig2 are intermediate targets that help guide facial motor neuron migration. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5492625 Thu, 01 Dec 2011 05:00:00 +0100 5492625 http://www.medworm.com/index.php?rid=5483096&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23706 AbstractIt has been established in several models that the p63 gene has an important role in the development of the epidermis and its derivatives. In Xenopus, only the ΔNp63 isoform of this gene has been cloned and its role during epidermal development remains unknown. In this work we showed that ΔNp63 is expressed in the non‐neural ectoderm since the gastrula stage and that it is regulated by the BMP4 signaling pathway. Our in vivo and in vitro experiments demonstrated that ΔNp63 is required in the earliest inductive steps of epidermal development. The overexpression of ΔNp63 caused an increase in epidermal markers with a suppression of neural induction while the blocking of ΔNp63 led to the opposite results. Finally, we found that ΔNp63 acts as an anti‐apoptotic gene, regulatin... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5483096 Thu, 01 Dec 2011 05:00:00 +0100 5483096 http://www.medworm.com/index.php?rid=5417635&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23703 AbstractSkeletal myogenesis is extensively influenced by the surrounding environment. However, how the extracellular matrix (ECM) affects morphogenesis of muscles is not well understood. We mapped the 3D organisation of fibronectin, tenascin and laminin by immunofluorescence during early epaxial myogenesis in mouse embryos. We define four stages of dermomyotome/myotome development and reveal the 3D organisation of myogenic cells within their ECM during those stages. Fibronectin is abundant in all interstitial tissues, while tenascin is restricted to intersegmental borders. Bundles of fibronectin and tenascin also penetrate into the myotome, possibly promoting myocyte alignment. A laminin matrix delineates the dermomyotome and myotome and undergoes dynamic changes, correlating with key deve... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5417635 Fri, 18 Nov 2011 00:31:26 +0100 5417635 http://www.medworm.com/index.php?rid=5465177&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.23703 AbstractSkeletal myogenesis is extensively influenced by the surrounding environment. However, how the extracellular matrix (ECM) affects morphogenesis of muscles is not well understood. We mapped the three‐dimensional (3D) organization of fibronectin, tenascin, and laminin by immunofluorescence during early epaxial myogenesis in mouse embryos. We define four stages of dermomyotome/myotome development and reveal the 3D organization of myogenic cells within their ECM during those stages. Fibronectin is abundant in all interstitial tissues, while tenascin is restricted to intersegmental borders. Bundles of fibronectin and tenascin also penetrate into the myotome, possibly promoting myocyte alignment. A laminin matrix delineates the dermomyotome and myotome and undergoes dynamic changes, co... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5465177 Tue, 15 Nov 2011 05:00:00 +0100 5465177 http://www.medworm.com/index.php?rid=5396820&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22773 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396820 Fri, 11 Nov 2011 10:33:36 +0100 5396820 http://www.medworm.com/index.php?rid=5396819&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22770 AbstractIn Xenopus laevis embryos, heparanase, the enzyme that degrades heparan sulfate, is synthesized as a preproheparanase (XHpaL) and processed to become enzymatically active (XHpa active). A short nonenzymatic heparanase splice variant (XHpaS) is also expressed. Using immunohistochemistry, Western blot, and heparanase promoter analysis, we studied the dynamic developmental expression of the three heparanases. Our results indicate that (1) all three isoforms are maternally expressed; (2) XHpaS is a developmental variant; (3) in the early embryo, heparanase is localized to both the plasma membrane and the nucleus; (4) several tissues express heparanase, but expression in the developing nervous system is most evident; (5) two promoters with distinct activities in different tissues drive ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396819 Fri, 11 Nov 2011 10:33:31 +0100 5396819 http://www.medworm.com/index.php?rid=5396818&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22776 AbstractThe T‐box transcription factor Tbx5 is involved in several developmental processes including cardiogenesis. Early steps of cardiac development are characterised by the formation of two cardiogenic lineages, the first (FHF) and the second heart field (SHF) lineage, which arise from a common cardiac progenitor cell population. To further investigate the function of Tbx5 during cardiogenesis, we generated a murine embryonic stem cell line constitutively overexpressing Tbx5. Differentiation of these cells is characterised by an earlier and increased appearance of contracting cardiomyocytes that beat with a higher frequency than control cells. In semi‐quantitative and quantitative RT‐PCR analyses, we observed an up‐regulation of cardiac marker genes such as Troponin T, endogenou... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396818 Fri, 11 Nov 2011 10:33:29 +0100 5396818 http://www.medworm.com/index.php?rid=5396817&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22784 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396817 Fri, 11 Nov 2011 10:33:24 +0100 5396817 http://www.medworm.com/index.php?rid=5396816&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22757 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396816 Fri, 11 Nov 2011 10:33:23 +0100 5396816 http://www.medworm.com/index.php?rid=5396815&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22783 AbstractMicroCT volume image of acetylated alpha‐tubulin immunostaining in a stage 23 chick embryo, immunostaining shown in yellow within the intact embryo. From Metscher and Müller, Developmental Dynamics 240:2301–2308, 2011. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396815 Fri, 11 Nov 2011 10:33:22 +0100 5396815 http://www.medworm.com/index.php?rid=5396812&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22787 AbstractThe early telencephalon shares molecular features with the early mid‐hindbrain region. In particular, these two developing brain areas each have a signaling center that secretes FGFs and an adjacent one that secretes WNTs. WNTs and FGFs each play essential roles in regulating cell fates in both the telencephalon and mid‐hindbrain. Despite this similarity, telencephalic and mid‐hindbrain precursors express distinct genes and ultimately generate different cell types, tissue morphologies, and neural functions. Here we show that genetically increasing the level of β‐catenin, a mediator of canonical WNT signaling, in the anterior neural plate causes a loss of telencephalic characteristics and a gain of mid‐hindbrain precursors express distinct genes and ultimately generate di... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396812 Fri, 11 Nov 2011 10:33:01 +0100 5396812 http://www.medworm.com/index.php?rid=5396814&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22782 Conclusions:Our findings have important implications for understanding how Otx proteins have subfunctionalized during evolution, and cement Drosophila as an effective tool to unravel the molecular bases of photoreceptor pathogenesis. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396814 Mon, 07 Nov 2011 05:00:00 +0100 5396814 http://www.medworm.com/index.php?rid=5396813&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22781 AbstractAnimal models that allow the visualization of specific classes of neurons are crucial for the study of the function of neuronal networks. We performed an enhancer trap screening in zebrafish and generated a collection of transgenic lines that expressed GFP in a spatially and temporally restricted manner. Among the fish generated, we found an insertion of the enhancer trap construct in the vicinity of the mnr2b/hlxb9lb gene encoding the mnx class of homeodomain transcription factor, which gave rise to GFP expression predominantly in spinal motor neurons and abducens motor neurons. During embryogenesis, GFP expression was also detected in endodermal and mesodermal tissues, where mnr2b is known to be expressed. These results indicate that the enhancer trap construct recapitulated the ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5396813 Mon, 07 Nov 2011 05:00:00 +0100 5396813 http://www.medworm.com/index.php?rid=5375349&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22786 AbstractMCS9.7 is a multispecies conserved sequence that has enhancer activity and is located 9.7 kb upstream of Interferon Regulatory Factor 6 (IRF6). This element contains DNA variation that is associated with cleft lip and palate, and contains a p63 binding site that transactivates IRF6 expression. To analyze whether the MCS9.7 enhancer is sufficient to drive IRF6 expression, we generated stable transgenic murine lines that carry a MCS9.7‐lacZ transgene. We observed that MCS9.7 activity recapitulated endogenous Irf6 expression in most tissues, but not in the medial edge epithelium (MEE) at E14.5, when Irf6 expression was high. Also, while MCS9.7 activity and Irf6 expression were associated with p63 expression, we observed MCS9.7 activity and Irf6 expression in periderm, although p63 w... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375349 Fri, 04 Nov 2011 04:00:00 +0100 5375349 http://www.medworm.com/index.php?rid=5375354&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22769 AbstractRetinoic acid receptor beta 2 (RARβ2) has been proposed as an important receptor mediating retinoid‐induced axonal growth and regeneration in developing mammalian spinal cord and brain. In urodele amphibians, organisms capable of extensive central nervous system (CNS) regeneration as adults, this receptor had not been isolated, nor had its function been characterized. We have cloned a full‐length RARβ2 cDNA from adult newt CNS. This receptor, NvRARβ2, is expressed in various adult organs capable of regeneration, including the spinal cord. Interestingly, both the NvRARβ2 mRNA and protein are up‐regulated during the first 2 weeks after amputation of the tail, primarily in the ependymoglial and meningeal tissues near the rostral cut surface of the cord. Treatment with LE135,... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375354 Wed, 02 Nov 2011 04:00:00 +0100 5375354 http://www.medworm.com/index.php?rid=5375353&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22774 AbstractAlthough regeneration is widespread among metazoa, the molecular mechanisms have been studied in only a handful of taxa. Of these taxa, fewer still are amenable to studies of embryogenesis. Our understanding of the evolution of regeneration, and its relation to embryogenesis, therefore remains limited. Using β‐catenin as a marker, we investigated the role of canonical Wnt signaling during both regeneration and embryogenesis in the cnidarian Nematostella vectensis. The canonical Wnt signaling pathway is known to play a conserved role in primary axis patterning in triploblasts. Induction of Wnt signaling with alsterpaullone results in ectopic oral tissue during both regeneration and embryogenesis by specifically upregulating β‐catenin expression, as measured by qRTPCR. Our data... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375353 Wed, 02 Nov 2011 04:00:00 +0100 5375353 http://www.medworm.com/index.php?rid=5375348&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22785 AbstractThe neural crest (NC) and placode are transient neurogenic cell populations that give rise to cranial ganglia of the vertebrate head. The formation of the anterior NC‐ and placode‐derived ganglia has been shown to depend on the single activity of either Neurog1 or Neurog2. The requirement of the more posterior cranial ganglia on Neurog1 and Neurog2 is unknown. Here we show that the formation of the NC‐derived parasympathetic otic ganglia, and placode‐derived visceral sensory petrosal and nodose ganglia are dependent on the redundant activities of Neurog1 and Neurog2. Tamoxifen‐inducible Cre lineage labeling of Neurog1 and Neurog2 show a dynamic spatiotemporal expression profile in both NC and epibranchial placode that correlates with the phenotypes of the Neurog‐mutant ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375348 Tue, 01 Nov 2011 04:00:00 +0100 5375348 http://www.medworm.com/index.php?rid=5375351&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22778 AbstractThe Crumbs family of transmembrane proteins have an important role in the differentiation of the apical membrane domain in various cell types, regulating such processes as epithelial cell polarization. The mammalian Crumbs protein family is composed of three members. Here, we inactivated the mouse Crb2 gene with gene‐targeting techniques, and found that the protein is crucial for early embryonic development with severe abnormalities appearing in Crb2‐deficient embryos at late‐gastrulation. Our findings indicate that the primary defect in the mutant embryos is disturbed polarity of the epiblast cells at the primitive streak, which affects epithelial to mesenchymal transition (EMT) during gastrulation, resulting in impaired mesoderm and endoderm formation, and embryonic lethali... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375351 Mon, 31 Oct 2011 04:00:00 +0100 5375351 http://www.medworm.com/index.php?rid=5375350&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22779 We present our work as a compelling example for the use of Drosophila as a model organism to study the molecular underpinnings of a complex human syndrome such as FOP. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375350 Mon, 31 Oct 2011 04:00:00 +0100 5375350 http://www.medworm.com/index.php?rid=5375356&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22771 AbstractCancer is driven by complex genetic and cellular mechanisms. Recently, the Drosophila community has become increasingly interested in exploring cancer issues. The Drosophila field has made seminal contributions to many of the mechanisms that are fundamental to the cancer process; several of these mechanisms have already been validated in vertebrates. Less well known are the Drosophila field's early direct contributions to the cancer field: some of the earliest tumor suppressors were identified in flies. In this review, we identify major contributions that Drosophila studies have made toward dissecting the pathways and mechanisms underlying tumor progression. We also highlight areas, such as drug discovery, where we expect Drosophila studies to make a major scientific impact in the ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375356 Fri, 28 Oct 2011 04:00:00 +0100 5375356 http://www.medworm.com/index.php?rid=5375355&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22766 AbstractSince the launch of the raft hypothesis in 1997, data generated in liposomes and cultured cells have highlighted the role of glycosphingolipids (GSLs) in the dynamic organization of biological membranes and the activity of signaling complexes. In parallel studies, genetic analysis of the GSL synthetic pathway has begun to reveal some of the specific roles of GSLs in vivo. Here, we review the role of GSLs in signaling in the context of a refined raft hypothesis. Recent genetic studies in worms, flies, and mice give us the opportunity to integrate these in vivo data with earlier in vitro liposome studies. Developmental Dynamics, 2012. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375355 Fri, 28 Oct 2011 04:00:00 +0100 5375355 http://www.medworm.com/index.php?rid=5375352&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22780 AbstractGene targeting in mice, first reported twenty‐five years ago, has led to monumental advances in the understanding of basic biology and human disease. The ability to employ a similarly straightforward method for gene manipulation in other experimental organisms would make their already significant contributions all the more powerful. Here, we briefly outline the strengths and weaknesses of reverse genetics techniques in non‐murine model organisms, ending with a more detailed description of two that promise to bring targeted gene modification to the masses: zinc finger nucleases (ZFNs) and transcription activator‐like effector nucleases (TALENs). One of the forefathers of ZFN technology, Dana Carroll, Ph.D,. and Bo Zhang, Ph.D., who was among the first to introduce TALEN target... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5375352 Fri, 28 Oct 2011 04:00:00 +0100 5375352 http://www.medworm.com/index.php?rid=5355391&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22764 AbstractDuring organogenesis in all multi‐cellular organisms, axial patterning is required to transform a single layer organ primordium into a three‐dimensional organ. The Drosophila eye model serves as an excellent model to study axial patterning. Dorso‐ventral (DV) axis determination is the first lineage restriction event during axial patterning of the Drosophila eye. The early Drosophila eye primordium has a default ventral fate, and the dorsal eye fate is established by onset of dorsal selector gene pannier (pnr) expression in a group of cells on the dorsal eye margin. The boundary between dorsal and ventral compartments called the equator is the site for Notch (N) activation, which triggers cell proliferation and differentiation. This review will focus on (1) chronology of event... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5355391 Thu, 27 Oct 2011 04:00:00 +0100 5355391 http://www.medworm.com/index.php?rid=5355393&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22765 AbstractThe 22q11.2 deletion syndrome is a common dominant genetic disorder characterized by a heterozygous deletion of a cluster of genes on chromosome 22q11.2. TBX1, a transcription factor belonging to the T‐box gene family, is a key player in the syndrome. However, heterozygosity of Tbx1 in mouse models does not fully recapitulate the phenotypes characteristic of the disease, which may point to the involvement of other genes in the deleted chromosomal region. Hence, we investigated the contribution of the catenin ARVCF, another gene that is deleted in 22q11.2DS. During Xenopus development, ARVCF mRNA is expressed in the pharyngeal arches and depleting either ARVCF or Tbx1 results in delayed migration of the cranial neural crest cells and in defects in the craniofacial skeleton and aor... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5355393 Tue, 25 Oct 2011 04:00:00 +0100 5355393 http://www.medworm.com/index.php?rid=5355392&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22721 AbstractThe novel adaptor protein Kazrin associates with multifunctional entities including p120‐subfamily members (ARVCF‐, delta‐, and p0071‐catenin). Critical contributions of Kazrin to development or homeostasis are indicated with respect to ectoderm formation, integrity and keratinocyte differentiation, whereas its presence in varied tissues suggests broader roles. We find that Kazrin is maternally loaded, is expressed across development and becomes enriched in the forming head. Kazrin's potential contributions to craniofacial development were probed by means of knockdown in the prospective anterior neural region. Cartilaginous head structures as well as eyes on injected sides were reduced in size, with molecular markers suggesting an impact upon neural crest cell establishment... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5355392 Tue, 25 Oct 2011 04:00:00 +0100 5355392 http://www.medworm.com/index.php?rid=5343511&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22775 AbstractEpithelial tubular organs are essential for life in higher organisms and include the pancreas and other secretory organs that function as biological factories for the synthesis and delivery of secreted enzymes, hormones and nutrients essential for tissue homeostasis and viability. The lungs, which are necessary for gas exchange, vocalization and maintaining blood pH, are organized as highly branched tubular epithelia. Tubular organs include arteries, veins and lymphatics, high‐speed passageways for delivery and uptake of nutrients, liquids, gases and immune cells. The kidneys and components of the reproductive system are also epithelial tubes. Both the heart and central nervous system of many vertebrates begin as epithelial tubes. Thus, it is not surprising that defects in tube f... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5343511 Mon, 24 Oct 2011 01:37:28 +0100 5343511 http://www.medworm.com/index.php?rid=5330651&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22762 AbstractThe inhibitor of differentiation Id2 is expressed in mesoderm of the second heart field, which contributes myocardial and mesenchymal cells to the primary heart tube. The role of Id2 in cardiac development is insufficiently known. Heart development was studied in sequential developmental stages in Id2 wildtype and knockout mouse embryos. Expression patterns of Id2, MLC‐2a, Nkx2.5, HCN4, and WT‐1 were analyzed. Id2 is expressed in myocardial progenitor cells at the inflow and outflow tract, in the endocardial and epicardial lineage, and in neural crest cells. Id2 knockout embryos show severe cardiac defects including abnormal orientation of systemic and pulmonary drainage, abnormal myocardialization of systemic and pulmonary veins, hypoplasia of the sinoatrial node, large intera... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330651 Wed, 19 Oct 2011 20:41:02 +0100 5330651 http://www.medworm.com/index.php?rid=5330650&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22760 AbstractA distinctive feature of embryonic tendon development is the steady increase in collagen fibril diameter and associated improvement of tissue mechanical properties. A potential mechanical stimulus for these changes is slow stretching of the tendon during limb growth. Testing this hypothesis in vivo is complicated by the presence of other developmental processes including muscle development and innervation. Here we used a cell culture tendon‐like construct to determine if slow stretch can explain the increases in fibril diameter and mechanical properties that are observed in vivo. Non‐stretched constructs had an ultrastructural appearance and mechanical properties similar to those of early embryonic tendon. However, slowly stretching during 4 days in culture increased collagen f... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330650 Wed, 19 Oct 2011 20:40:56 +0100 5330650 http://www.medworm.com/index.php?rid=5330649&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22761 AbstractThe establishment of rat embryonic stem cells constitutes a precious tool since rat has been extensively used in biomedical research, in particular for the generation of human neurodisease animal models. Up to now only a few studies have described the isolation of rat embryonic stem‐like cells. One out of 9 isolated rat embryonic stem‐like cell lines (B1‐RESC) obtained from a 4.5‐day post‐coitum blastocyst were extensively characterized and kept in culture for up to 80 passages on feeders with LIF. The stable growth of these cells and the expression of pluripotent markers were confirmed up to a high number of passages in culture, also in the absence of feeders and LIF. B1‐RESC expresses the three germ layers markers both in vitro, within differentiating embryoid bodies,... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330649 Wed, 19 Oct 2011 20:40:51 +0100 5330649 http://www.medworm.com/index.php?rid=5330648&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22756 AbstractTwo positional characteristics of the ciliary axoneme—its location on the plasma membrane as it emerges from the cell, and its orientation in three‐dimensional (3D) space—are known to be critical for optimal function of actively motile cilia (including nodal cilia), as well as for modified cilia associated with special senses. However, these positional characteristics have not been analyzed to any significant extent for primary cilia. This review briefly summarizes the history of knowledge of these two positional characteristics across a wide spectrum of cilia, emphasizing their importance for proper function. Then the review focuses what is known about these same positional characteristics for primary cilia in all major tissue types where they have been reported. The review ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330648 Wed, 19 Oct 2011 20:40:43 +0100 5330648 http://www.medworm.com/index.php?rid=5330647&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22768 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330647 Wed, 19 Oct 2011 20:40:40 +0100 5330647 http://www.medworm.com/index.php?rid=5330646&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22732 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330646 Wed, 19 Oct 2011 20:40:39 +0100 5330646 http://www.medworm.com/index.php?rid=5330645&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22767 AbstractE13 mouse submandibular salivary gland (SMG) cultured for 24 hours ex vivo and immunostained for collagen IV (blue) to mark the basement membrane, Na+/K+ ATPase (green) which is preferential for the epithelium, and the focal adhesion protein vinculin (red) to delineate cell‐matrix adhesions. Note that vinculin localizes the most strongly to regions of cell‐matrix contact immediately adjacent to the basement membrane. From Daley et al., Developmental Dynamics 240:2069–2083, 2011. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330645 Wed, 19 Oct 2011 20:40:37 +0100 5330645 http://www.medworm.com/index.php?rid=5330643&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22772 AbstractNeuromuscular synapse formation requires an exchange of signals between motor neurons and muscle. Agrin, supplied by motor neurons, binds to Lrp4 in muscle, stimulating phosphorylation of MuSK and recruitment of a signaling complex essential for synapse‐specific transcription and anchoring of key proteins in the postsynaptic membrane. Lrp4, like the LDLR and other Lrp‐family members, contains an intracellular region with motifs that can regulate receptor trafficking, as well as assembly of an intracellular signaling complex. Here, we show that the intracellular region of Lrp4 is dispensable for Agrin to stimulate MuSK phosphorylation and clustering of acetylcholine receptors in cultured myotubes. Moreover, muscle‐selective expression of a Lrp4‐CD4 chimera, composed of the e... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330643 Wed, 19 Oct 2011 20:40:21 +0100 5330643 http://www.medworm.com/index.php?rid=5330644&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22776 AbstractThe T‐box transcription factor Tbx5 is involved in several developmental processes including cardiogenesis. Early steps of cardiac development are characterised by the formation of two cardiogenic lineages, the first (FHF) and the second heart field (SHF) lineage which arise from a common cardiac progenitor cell population. To further investigate the function of Tbx5 during cardiogenesis, we generated a murine ES cell line constitutively overexpressing Tbx5. Differentiation of these cells is characterised by an earlier and increased appearance of contracting cardiomyocytes that beat with a higher frequency than control cells. In semi‐quantitative and quantitative RT‐PCR analyses, we observed an upregulation of cardiac marker genes such as Troponin T, endogenous Tbx5, and Nkx2... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5330644 Mon, 17 Oct 2011 04:00:00 +0100 5330644 http://www.medworm.com/index.php?rid=5292921&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22758 AbstractThe Rab family of small GTPases function as molecular switches regulating membrane and protein trafficking. Individual Rab isoforms define and are required for specific endosomal compartments. To facilitate in vivo investigation of specific Rab proteins, and endosome biology in general, we have generated transgenic zebrafish lines to mark and manipulate Rab proteins. We also developed software to track and quantify endosome dynamics within time‐lapse movies. The established transgenic lines ubiquitously express EGFP fusions of Rab5c (early endosomes), Rab11a (recycling endosomes), and Rab7 (late endosomes) to study localization and dynamics during development. Additionally, we generated UAS‐based transgenic lines expressing constitutive active (CA) and dominant‐negative (DN) ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5292921 Tue, 04 Oct 2011 04:00:00 +0100 5292921 http://www.medworm.com/index.php?rid=5281476&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22759 AbstractRenewing tissues in the adult organism such as the gastrointestinal (GI) epithelium depend on stem cells for epithelial maintenance and repair. Yet, little is known about the developmental origins of adult stem cells and their niches. Studies of Drosophila adult midgut precursors (AMPs), a population of endodermal progenitors, demonstrate that adult intestinal stem cells (ISCs) arise from the AMP lineage and provide insight into the stepwise process by which the adult midgut epithelium is established during development. Here, I review the current literature on AMPs, where local, inductive and long‐range humoral signals have been found to control progenitor cell behavior. Future studies will be necessary to determine the precise mechanism by which adult intestinal stem cells are e... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5281476 Mon, 03 Oct 2011 04:00:00 +0100 5281476 http://www.medworm.com/index.php?rid=5281475&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22751 In this study, we examined this process by reconstructing three‐dimensional images from serial sections of larvae. We show that the left coelom developed by both schizocoely and enterocoely from the archenteron tip, whereas the hydrocoel and right coelom formed by enterocoely from the archenteron. This coelom formation arranged the coelomic compartments directly along the adult oral‐aboral axis by skipping the initial bilateral phases. Furthermore, our data indicate P. japonica retains ancestral asymmetry along the left‐right axis in the location of the adult rudiment. Developmental Dynamics, 2011. © 2011 Wiley Periodicals, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5281475 Mon, 03 Oct 2011 04:00:00 +0100 5281475 http://www.medworm.com/index.php?rid=5310752&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22763 AbstractThe human transcription factors (TFs) GATA4, NKX2.5, and TBX5 form part of the core network necessary to build a human heart and are involved in Congenital Heart Diseases (CHDs). The human natriuretic peptide precursor A (NPPA) and α‐myosin heavy chain 6 (MYH6) genes are downstream effectors involved in mammalian cardiogenesis that have been demonstrated to be in vitro targets of such TFs. To determine whether GATA4, NKX2.5, and TBX5 TFs are able to transactivate the enhancers of these human downstream effector genes in vivo, we overexpressed them in the whole Drosophila cardiac tube. We observed that all three TFs up‐regulate their natural target enhancers in Drosophila and cause developmental defects. This novel system could be used to determine in vivo the genetic nature of... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5310752 Sat, 01 Oct 2011 04:00:00 +0100 5310752 http://www.medworm.com/index.php?rid=5292920&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22752 AbstractMuenke syndrome caused by the FGFR3P250R mutation is an autosomal dominant disorder mostly identified with coronal suture synostosis, but it also presents with other craniofacial phenotypes that include mild to moderate midface hypoplasia. The Muenke syndrome mutation is thought to dysregulate intramembranous ossification at the cranial suture without disturbing endochondral bone formation in the skull. We show in this study that knock‐in mice harboring the mutation responsible for the Muenke syndrome (FgfR3P244R) display postnatal shortening of the cranial base along with synchondrosis growth plate dysfunction characterized by loss of resting, proliferating and hypertrophic chondrocyte zones and decreased Ihh expression. Furthermore, premature conversion of resting chondrocytes ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5292920 Sat, 01 Oct 2011 04:00:00 +0100 5292920 http://www.medworm.com/index.php?rid=5281474&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22755 AbstractEarly placental development in mice involves patterning of the chorion into distinct layers, though little is understood regarding the interactions that regulate its organization. Here we demonstrate that keratin aggregates found in Mrj−/− chorionic trophoblast cells are associated with abnormal cell morphology, collapse of the actin cytoskeleton, E‐cadherin and β‐catenin misexpression and extracellular matrix (ECM) disorganization. Accordingly, Mrj−/− trophoblast cells in vitro are nonadherent and display erratic migratory behavior. These cells also fail to differentiate into syncytiotrophoblast cells since Rhox4b expression, a marker of syncytiotrophoblast progenitors, was maintained and Gcm1, Synb, and Syna expression failed to increase. This differentiation defect ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5281474 Sat, 01 Oct 2011 04:00:00 +0100 5281474 http://www.medworm.com/index.php?rid=5268630&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22754 AbstractThe separation and specification of mesoderm into the notochord and somites involves members of the non‐clustered δ‐protocadherins. Axial (AXPC) and paraxial (PAPC) protocadherins are expressed in the early dorsal mesoderm and later become refined to the developing notochordal and somitic mesoderm, respectively. The role of PAPC in this process has been studied extensively, but the role of AXPC is poorly understood. Partial knockdown of AXPC causes a specific bent‐axis phenotype, while more severe knockdown results in the loss of notochord formation. The inability of these embryos to develop a notochord is not due to a cell‐sorting event via changes in cell adhesion during gastrulation, but rather this defect is manifested through the loss of axial mesoderm specification, ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5268630 Fri, 30 Sep 2011 11:50:39 +0100 5268630 http://www.medworm.com/index.php?rid=5268631&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22749 AbstractOverlaps in spatial patterns of gene expression are frequently an initial clue to genetic interactions during embryonic development. However, manual inspection of images requires considerable time and resources impeding the discovery of important interactions because tens of thousands of images exist. The FlyExpress discovery platform was developed to facilitate data‐driven comparative analysis of expression pattern images from Drosophila embryos. An image‐based search of the BDGP and Fly‐FISH datasets conducted in FlyExpress yields fewer but more precise results than text‐based searching when the specific goal is to find genes with overlapping expression patterns. We also provide an example of a FlyExpress contribution to scientific discovery: an analysis of gene expressio... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5268631 Thu, 29 Sep 2011 04:00:00 +0100 5268631 http://www.medworm.com/index.php?rid=5257270&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22745 AbstractThe transcription factor Pax7 is a marker and regulator of muscle progenitors and satellite cells that contribute to the embryonic development and postembryonic growth of skeletal muscle in vertebrates, as well as to its repair and regeneration. Here, we identify Pax7+ve myogenic cells in the zebrafish and characterize their behavior in postembryonic stages. Mononucleate Pax7+ve cells can first be found associated with myofibers at 72 hours post fertilization (hpf). To follow the behavior of muscle progenitor cells in vivo, we generated transgenic lines expressing fluorescent proteins under the control of the pax7a or pax3a promoters. We established an injury model using cardiotoxin injection and monitored cell proliferation and myogenic regulatory factor expression in myogenic pre... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5257270 Tue, 27 Sep 2011 02:45:24 +0100 5257270 http://www.medworm.com/index.php?rid=5257274&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22753 AbstractUnderstanding the molecular basis of wound healing and regeneration in vertebrates is one of the main challenges in biology and medicine. This understanding will lead to medical advances allowing accelerated tissue repair after wounding, rebuilding new tissues/organs and restoring homeostasis. Drosophila has emerged as a valuable model for studying these processes because the genetic networks and cytoskeletal machinery involved in epithelial movements occurring during embryonic dorsal closure, larval imaginal disc fusion/regeneration, and epithelial repair are similar to those acting during wound healing and regeneration in vertebrates. Recent studies have also focused on the use of Drosophila adult stem cells to maintain tissue homeostasis. Here, we review how Drosophila has contr... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5257274 Mon, 26 Sep 2011 04:00:00 +0100 5257274 http://www.medworm.com/index.php?rid=5257273&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22744 AbstractYeast Periodic tryptophan protein 2 gene (Pwp2) is involved in ribosome biogenesis and has been implicated in regulation of the cell cycle in yeast. Here, we report a zebrafish protein‐trap line that produces fluorescently tagged Periodic tryptophan protein 2 gene homologue (Pwp2h) protein, which can be dynamically tracked in living fish at subcellular resolution. We identified both full‐length zebrafish Pwp2h and a short variant. The expression results show that Pwp2h is present in numerous sites in the early developing embryo, but later is restricted to highly proliferative regions, including the forebrain ventricular zone and endoderm‐derived organs in the early larval stage. At the subcellular level, Pwp2h protein appears to be localized to the region of the nucleolus con... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5257273 Mon, 26 Sep 2011 04:00:00 +0100 5257273 http://www.medworm.com/index.php?rid=5257272&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22750 AbstractHepatocyte growth factor–regulated tyrosine kinase substrate that is encoded by Hgs promotes degradation of ubiquitinated signaling molecule in the early endosome. We previously reported that a targeted mutation in Hgs results in embryonic lethality soon after gastrulation in the mouse. Here, we report that downstream target genes for BMP signaling were highly down‐regulated in the Hgs mutant embryos. We also showed that Hgs is required for phosphorylation of SMAD1/5/8 and TAK1/p38 to transduce BMP signaling. Furthermore, we found that HGS functions to localize TAK1 in early endosome for its activation. These results suggest that HGS is critical to localize TAK1 to early endosome for transducing BMP signaling for proper development. Our data revealed a new mechanism to modify B... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5257272 Mon, 26 Sep 2011 04:00:00 +0100 5257272 http://www.medworm.com/index.php?rid=5257271&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22748 In this study, we used various genetically modified mouse models to investigate tissue interaction between the condyle and glenoid fossa during TMJ formation in mice. We report that either absence or dislocation of the condyle results in an arrested glenoid fossa development. In both cases, glenoid fossa development was initiated, but failed to sustain, and became regressed subsequently. However, condyle development appears to be independent upon the presence of the forming glenoid fossa. In addition, we show that substitution of condyle by Meckel's cartilage is able to sustain glenoid fossa development. These observations suggest that proper signals from the developing condyle or Meckel's cartilage are required to sustain the glenoid fossa development. Developmental Dynamics, 2011. © 201... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5257271 Mon, 26 Sep 2011 04:00:00 +0100 5257271 http://www.medworm.com/index.php?rid=5246321&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22740 AbstractTo many scientists, the word “networking” sounds like an enterprise only suitable for those who run in circles with the business elite. However in reality, most scientists depend on networking to generate and maintain professional relationships, disseminate and gather information, and to climb the professional ladder. Presented here are tips from three seasoned professors, Kathy Cheah, PhD, Susan Mango, PhD, and Randall Moon, PhD, who describe what networking means to them, why it is important, and how they go about doing it. Developmental Dynamics, 2011. © 2011 Wiley‐Liss, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5246321 Fri, 23 Sep 2011 10:35:55 +0100 5246321 http://www.medworm.com/index.php?rid=5246322&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22741 AbstractProstate development is influenced by β‐catenin signaling, but it is unclear which β‐catenin activators are involved, where they are synthesized, and whether their mRNA abundance is influenced by androgens. We identified WNT/β‐catenin‐responsive β‐galactosidase activity in the lower urogenital tract (LUT) of transgenic reporter mice, but β‐galactosidase activity differed among the four mouse strains we examined. We used in situ hybridization to compare patterns of Wnts, r‐spondins (Rspos, co‐activators of β‐catenin signaling), β‐catenin‐responsive mRNAs, and an androgen receptor‐responsive mRNA in wild type fetal male, fetal female, and neonatal male LUT. Most Wnt and Rspo mRNAs were present in LUT during prostate development. Sexually dimorphic expre... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5246322 Tue, 20 Sep 2011 04:00:00 +0100 5246322 http://www.medworm.com/index.php?rid=5233461&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22731 AbstractT‐box gene Tbx4 is critical for the formation of the umbilicus and the initiation of the hindlimb. Previous studies show broad expression in the allantois, hindlimb, lung and proctodeum. We have examined the expression of Tbx4 in detail and used a Tbx4‐Cre line to trace the fates of Tbx4‐expressing cells. Tbx4 expression and lineage reveal that various distinct appendages, such as the allantois, hindlimb, and external genitalia, all arise from a single mesenchymal expression domain. Additionally, although Tbx4 is associated primarily with the hindlimb, we find two forelimb expression domains. Most notably, we find that, despite the requirement for Tbx4 in allantoic vasculogenesis, the presumptive endothelial cells of the allantois do not express Tbx4 and lineage tracing revea... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233461 Tue, 20 Sep 2011 00:44:49 +0100 5233461 http://www.medworm.com/index.php?rid=5233459&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22747 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233459 Tue, 20 Sep 2011 00:44:40 +0100 5233459 http://www.medworm.com/index.php?rid=5233458&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22707 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233458 Tue, 20 Sep 2011 00:44:38 +0100 5233458 http://www.medworm.com/index.php?rid=5233457&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22746 AbstractDeveloping embryos of the self‐fertilising mangrove killifish Kryptolebias marmoratus. PTU‐treated embryo (left) lacking melanin pigmentation and a normal embryo (right), 10 days post‐fertilisation. Due to its ability to self‐fertilise, this species proves to be a highly useful embryological model with unique genetics. From Mourabit et al., Developmental Dynamics 240:1694–1704, 2011. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233457 Tue, 20 Sep 2011 00:44:37 +0100 5233457 http://www.medworm.com/index.php?rid=5233450&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22737 AbstractThe word “nociception” is derived from the Latin “nocere,” which means “to harm.” Nociception refers to the sensory perception of noxious stimuli that have the potential to cause tissue damage. Since the perception of such potentially harmful stimuli often results in behavioral escape responses, nociception provides a protective mechanism that allows an organism to avoid incipient (or further) damage to the tissue. It appears to be universal in metazoans as a variety of escape responses can be observed in both mammalian and non‐mammalian vertebrates, as well as diverse invertebrates such as leeches, nematodes, and fruit flies (Sneddon [2004] Brain Research Review 46:123–130; Tobin and Bargmann [2004] Journal of Neurobiology 61:161–174; Smith and Lewin [2009] Journ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233450 Tue, 20 Sep 2011 00:44:26 +0100 5233450 http://www.medworm.com/index.php?rid=5233454&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22743 We present here the sequence and embryonic expression patterns for the zebrafish tfe3b, tfeb, and tfec genes, and identify a new isoform of tfe3a. These findings will assist in elucidating the roles of the MiT gene family over the course of vertebrate evolution. Developmental Dynamics, 2011. © 2011 Wiley‐Liss, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233454 Mon, 19 Sep 2011 04:00:00 +0100 5233454 http://www.medworm.com/index.php?rid=5233453&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22742 AbstractWe have generated a line of transgenic zebrafish, Tg(dat:EGFP), in which the green fluorescent protein (GFP) is expressed under the control of cis‐regulatory elements of the dopamine transporter (dat) gene. In Tg(dat:EGFP) fish, dopamine (DA) neurons are labeled with GFP, including those in ventral diencephalon (vDC) clusters, amacrine cells in the retina, in the olfactory bulb, in the pretectum, and in the caudal hypothalamus. In the vDC, DA neurons of groups 2–6 are correctly labeled with GFP, based on colocalization analyses. MPTP (1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine) treatments induced a modest but significant loss of DA neurons in groups 2–6 of the vDC. This transgenic line will be useful for the study of DA neuron development and in models of DA neuro... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233453 Mon, 19 Sep 2011 04:00:00 +0100 5233453 http://www.medworm.com/index.php?rid=5233452&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22739 AbstractGenerating diverse neurons in the central nervous system involves three major steps. First, heterogeneous neural progenitors are specified by positional cues at early embryonic stages. Second, neural progenitors sequentially produce neurons or intermediate precursors that acquire different temporal identities based on their birth‐order. Third, sister neurons produced during asymmetrical terminal mitoses are given distinct fates. Determining the molecular mechanisms underlying each of these three steps of cellular diversification will unravel brain development and evolution. Drosophila has a relatively simple and tractable CNS, and previous studies on Drosophila CNS development have greatly advanced our understanding of neuron fate specification. Here we review those studies and d... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233452 Mon, 19 Sep 2011 04:00:00 +0100 5233452 http://www.medworm.com/index.php?rid=5233451&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22738 AbstractThe compound eye of Drosophila melanogaster consists of individual subunits (“ommatidia”), each containing photoreceptors and support cells. These cells derive from an undifferentiated epithelium in the eye imaginal disc and their differentiation follows a highly stereotypic pattern. Sequential commitment of pluripotent cells to become specialized cells of the visual system serves as a unique model system to study basic mechanisms of tissue development. In the past years, many regulatory genes that govern the development of the compound eye have been identified and their mode of action genetically dissected. Transcription factor networks in combination with cell–cell signalling pathways regulate the development of the eye tissue in a precise temporal and spatial manner. Here,... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233451 Mon, 19 Sep 2011 04:00:00 +0100 5233451 http://www.medworm.com/index.php?rid=5233455&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22736 AbstractPlanar polarity is generated through the activity of two groups of proteins, the “core” system and the Fat (Ft)/Dachsous (Ds) system. Although both are conserved from insects to mammals, vertebrate studies into planar polarity have primarily focussed on core planar polarity proteins and have only recently branched into the study of the Ft/Ds system. In Drosophila, however, years of detailed analysis have started to elucidate some of the mechanisms by which Ft/Ds signalling might set up polarity across a tissue, and how this may impact upon core protein‐mediated planar polarity. In this review, we discuss the major findings, models, and controversies that have emerged from Drosophila research into the Ft/Ds system, and indicate some areas for further investigation. Development... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5233455 Wed, 14 Sep 2011 04:00:00 +0100 5233455 http://www.medworm.com/index.php?rid=5204176&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22735 AbstractNeural crest cells give rise to a diverse range of structures during vertebrate development. These cells initially exist in the dorsal neuroepithelium and subsequently acquire the capacity to migrate. Although studies have documented the importance of adherens junctions in regulating neural crest cell migration, little attention has been paid to tight junctions during this process. We now identify the tight junction protein cingulin as a key regulator of neural crest migration. Cingulin knock‐down increases the migratory neural crest cell domain, which is correlated with a disruption of the neural tube basal lamina. Overexpression of cingulin also augments neural crest cell migration and is associated with similar basal lamina changes and an expansion of the premigratory neural c... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5204176 Thu, 08 Sep 2011 04:00:00 +0100 5204176 http://www.medworm.com/index.php?rid=5204175&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22734 AbstractCharacterization and functional manipulation of specific groups of neurons in the vertebrate central nervous system (CNS) remains a major hurdle for understanding complex circuitry and functions. In zebrafish, the Gal4/UAS system has permitted expression of transgenes and enhancer trap screens, but is often limited by broad expression domains. We have developed a method for cell‐type specific expression using Gal80 inhibition of Gal4‐dependent expression. We show that native Gal4 is able to drive strong expression, that Gal80 can inhibit this expression, and that overlapping Gal4 and Gal80 expression can achieve “intersectional” expression in spatially and genetically defined subsets of neurons. We also optimize Gal80 for expression in vertebrates, track Gal80 expression wi... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5204175 Thu, 08 Sep 2011 04:00:00 +0100 5204175 http://www.medworm.com/index.php?rid=5204179&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22733 We present a broadly applicable procedure for whole‐mount imaging of antibody probes in embryonic tissues at microscopic resolutions based on combining a metal‐based immunodetection scheme with x‐ray microtomography (microCT). The method is generally accessible, relying on standard enzyme‐conjugated secondary antibodies and other readily available reagents, and is demonstrated here with microCT visualizations of acetylated α‐tubulin in the chick nervous system and of type II collagen in developing limbs. The tomographic images offer complete three‐dimensional representations of molecular patterns obtained with immunostaining methods at the level of organ development, with added possibilities to quantify both spatial distributions and varying densities of gene products in situ.... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5204179 Wed, 07 Sep 2011 04:00:00 +0100 5204179 http://www.medworm.com/index.php?rid=5204178&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22729 AbstractThe integration of the brain and face and to what extent this relationship constrains or enables evolutionary change in the craniofacial complex is an issue of long‐standing interest in vertebrate evolution. To investigate brain‐face integration, we studied the covariation between the forebrain and midface at gestational days 10–10.5 in four strains of laboratory mice. We found that phenotypic variation in the forebrain is highly correlated with that of the face during face formation such that variation in the size of the forebrain correlates with the degree of prognathism and orientation of the facial prominences. This suggests strongly that the integration of the brain and face is relevant to the etiology of midfacial malformations such as orofacial clefts. This axis of int... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5204178 Wed, 07 Sep 2011 04:00:00 +0100 5204178 http://www.medworm.com/index.php?rid=5204177&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22722 AbstractSomitogenesis is a complex process during early vertebrate development involving interactions between many factors to form a bilateral somite series. A role for chromatin remodelers in somitogenesis has not yet been demonstrated. Here, we investigate the function of chromodomain helicase DNA binding protein 7 (chd7) during zebrafish somitogenesis. We show that Chd7 deficiency leads to asymmetric segmentation of the presomitic mesoderm (PSM), as revealed by expression of the somitogenesis genes, cdx1a, dlc, her7, mespa, and ripply1. Moreover, we show that abrogation of Chd7 results in the loss of asymmetric expression of spaw in the lateral plate mesoderm, which is consistent with more general laterality defects. Based on the observation that insufficient Chd7 leads to left–right ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5204177 Wed, 07 Sep 2011 04:00:00 +0100 5204177 http://www.medworm.com/index.php?rid=5204174&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22730 AbstractEpithelial‐stromal interactions in the lower urogenital tract (LUT) are integral to prostatic and seminal vesicle development in males, vaginal and uterine development in females, and urethral development in both sexes. Gene expression profiling of isolated LUT stroma and epithelium has unraveled mechanisms of LUT development, but such studies are confounded by heterogeneous and ill‐defined cell sub‐populations contained within each tissue compartment. We used in situ hybridization to synthesize a high‐resolution molecular atlas of 17‐day post‐coitus fetal mouse LUT. We identified mRNAs that mark selective cell populations of the seminal vesicle, ejaculatory duct, prostate, urethra, and vagina, subdividing these tissues into 16 stromal and 8 epithelial sub‐compartment... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5204174 Thu, 01 Sep 2011 04:00:00 +0100 5204174 http://www.medworm.com/index.php?rid=5191182&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22726 AbstractIn mammals, the Prostaglandin D2 (PGD2) signaling pathway is involved in male gonadal development, regulating Sox9 gene expression and SOX9 protein subcellular localization through lipocalin prostaglandin D synthase (L‐Pgds) activity. Nevertheless, because L‐Pgds is downstream of Sox9, its expression cannot explain the initial nuclear translocation of the SOX9 protein. Here, we show that another source of PGD2, hematopoietic‐Pgds (H‐Pgds) enzyme is expressed in somatic and germ cells of the embryonic gonad of both sexes, as early as embryonic day (E) 10.5, before the onset of L‐Pgds expression. Inhibition of H‐Pgds activity by the specific HQL‐79 inhibitor leads to impaired nuclear translocation of SOX9 protein in E11.5 Sertoli cells. Furthermore, analysis of H‐Pgds... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5191182 Wed, 31 Aug 2011 23:00:00 +0100 5191182 http://www.medworm.com/index.php?rid=5179223&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22724 AbstractThe proepicardium is a transient embryonic structure that is a source of precursors of the epicardium, coronary smooth muscle cells, and may be a source of coronary endothelial cells (EC). To better understand proepicardium development a systematic analysis of EC appearance was performed. Multiple marker analysis showed that EC are present in the mouse proepicardium at embryonic day (E) 9.0 through E9.75. Distinct populations of EC were found that were associated with the liver bud, and the sinus venosus, as well as a population that do not appear to be associated with either of these structures. There was a temporal increase in the number of EC and temporal changes in the distribution of EC within the different populations during PE development. These findings indicate that EC exi... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5179223 Wed, 31 Aug 2011 03:18:47 +0100 5179223 http://www.medworm.com/index.php?rid=5179224&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22728 AbstractPhylogenetic footprinting has revealed that cis‐regulatory modules consist of clusters of conserved DNA sequences. We have generated a Drosophila melanogaster genomic database of conserved sequence clusters (CSCs) to facilitate enhancer discovery and analysis of their sub‐structure. The database consists of >100,000 CSCs gleaned from EvoPrints spanning over 90% of the genome. To identify related enhancers based on shared conserved sequence elements, we have developed database search and alignment algorithms, collectively known as cis‐Decoder. These web‐accessible tools initially identify conserved repeat elements within an EvoPrinted input enhancer and then search the database for CSCs that score highly against the input enhancer. To demonstrate the utility of these tool... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5179224 Mon, 29 Aug 2011 23:00:00 +0100 5179224 http://www.medworm.com/index.php?rid=5168879&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22725 AbstractThe bipolar spindle is a complex molecular machinery that drives chromosome congression and segregation. During meiosis in the mouse multiple microtubule organizing centers aggregate to form a bipolar intermediate followed by elongation and establishment of the barrel‐shaped acentriolar meiotic spindle. Previous studies have shown that septin1 is localized to spindle poles in mitosis, suggesting its possible involvement in spindle assembly. We, therefore, asked whether perturbation of septin1 will impair the process of spindle assembly and investigated localization and function during mouse oocyte meiotic maturation. Septin1 was localized to the spindle at metaphase and at the midbody during cytokinesis. Disruption of septin1 function using siRNA caused a decrease in PBE and exte... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5168879 Sun, 28 Aug 2011 01:38:47 +0100 5168879 http://www.medworm.com/index.php?rid=5168880&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22727 AbstractThe highly conserved POU genes encode homeodomain transcription factors involved in various developmental events, with some, the Brn genes, playing key roles in neurogenesis. We investigated the evolutionary relationships between these genes, by studying the POU gene complement of a model teleost, the medaka (Oryzias latipes). We identified 17 POU genes and carried out a comprehensive in situ hybridization analysis focusing on the optic tectum, a cortical structure of the mesencephalon, in which cell positions and their differentiation states are spatially and temporally correlated. Six POU genes displayed patterned expression in the optic tectum: two genes were expressed in the center of the organ (a zone with differentiated neurons), two in an intermediate zone in which cells exi... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5168880 Thu, 25 Aug 2011 23:00:00 +0100 5168880 http://www.medworm.com/index.php?rid=5155624&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22716 In this study, we have investigated the role of Tcf7l1 (formerly named Tcf3) in maintaining spinal progenitor characteristics and allowing the continued production of neurons and glia following primary neurogenesis. We find that spinal cord progenitor markers are progressively lost in embryos lacking Tcf7l1, and that the number of proliferative progenitors decreases accordingly. Furthermore, we show that the production of both neuronal and glial secondary derivatives of the pMN progenitor pool requires Tcf7l1. Together, these results indicate that Tcf7l1 plays an important role in spinal cord progenitor maintenance, indicating that this core function is conserved throughout multiple epithelial cell populations. Developmental Dynamics, 2011. © 2011 Wiley‐Liss, Inc. (Source: Developmental... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5155624 Thu, 25 Aug 2011 07:39:16 +0100 5155624 http://www.medworm.com/index.php?rid=5168882&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22723 AbstractThe Hippo signaling pathway emerged from studies of Drosophila tumor suppressor genes, and is now appreciated as a major growth control pathway in vertebrates as well as arthropods. As a recently discovered pathway, key components of the pathway are continually being identified, and new insights into how the pathway is regulated and deployed are arising at a rapid pace. Over the past year and a half, significant advances have been made in our understanding of upstream regulatory inputs into Hippo signaling, key negative regulators of Hippo pathway activity have been identified, and important roles for the pathway in regeneration have been described. This review describes these and other advances, focusing on recent progress in our understanding of Hippo signaling that has come from... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5168882 Wed, 24 Aug 2011 23:00:00 +0100 5168882 http://www.medworm.com/index.php?rid=5168881&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22720 Abstractprdm1 is an important transcriptional regulator that plays diverse roles during development of a wide variety of vertebrate and invertebrate species. prdm1 is required for neural crest specification in zebrafish, but not in mouse embryos. The role of this gene in neural crest formation in other species has not been examined, and its regulation during embryonic development is poorly understood. Here, we investigate the expression pattern, function, and the upstream regulatory inputs into prdm1 during lamprey neural crest development. prdm1 is strongly expressed in the lamprey neural plate border, suggesting a conserved ancestral role of this gene in the neural crest formation. We found that lamprey neural plate border expression of prdm1 is activated by Ap‐2 and Msx, but is indepe... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5168881 Wed, 24 Aug 2011 23:00:00 +0100 5168881 http://www.medworm.com/index.php?rid=5155625&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22717 AbstractWe found by electron microscopy that the inter‐membrane space of embryonic stem cells is irregular and generally wider than in differentiated cells. Among a panel of nuclear envelope structural proteins examined, the expression of Syne1/nesprin‐1 was found to be greatly induced upon differentiation. Down‐regulation of Syne1 by siRNA in differentiated embryonic stem cells caused the nuclear envelope to adopt a configuration resembling that found in undifferentiated embryonic stem cells. Suppression of Syne1 expression did not produce a detectable impact on the retinoic acid–induced differentiation of embryonic stem cells; however, forced expression of Syne1 enhanced the tendency of the cells to lose pluripotency. Thus, we found that low expression of Syne1 splicing isoforms ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5155625 Mon, 22 Aug 2011 23:00:00 +0100 5155625 http://www.medworm.com/index.php?rid=5137839&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22710 AbstractIn contrast to mammals, the brain of the adult zebrafish has a remarkable ability to regenerate. In mammals, injuries induce proliferation of astrocytes and oligodendrocyte progenitors contributing to the formation of a glial scar. We analyzed the proliferation of glial cells and microglia in response to stab injury in the adult zebrafish telencephalon: Radial glial markers were up‐regulated at the ventricle and co‐expressed the proliferation nuclear antigen (PCNA). Microglia and oligodendrocyte progenitors accumulated transiently at the site of lesion. However, we could not find evidence of permanent scar formation. Parenchymal proliferation was almost negligible in comparison to the increase in proliferation at the ventricular zone. This suggests that most of the cellular mat... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137839 Wed, 17 Aug 2011 17:08:00 +0100 5137839 http://www.medworm.com/index.php?rid=5137838&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22713 AbstractHuman palatal clefting is debilitating and difficult to rectify surgically. Animal models enhance our understanding of palatogenesis and are essential in strategies designed to ameliorate palatal malformations in humans. Recent studies have shown that the zebrafish palate, or anterior neurocranium, is under similar genetic control to the amniote palatal skeleton. We extensively analyzed palatogenesis in zebrafish to determine the similarity of gene expression and function across vertebrates. By 36 hours postfertilization (hpf) palatogenic cranial neural crest cells reside in homologous regions of the developing face compared with amniote species. Transcription factors and signaling molecules regulating mouse palatogenesis are expressed in similar domains during palatogenesis in zeb... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137838 Wed, 17 Aug 2011 17:07:59 +0100 5137838 http://www.medworm.com/index.php?rid=5137837&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22709 We present evidence that S100a8, without S100a9, has a previously unrecognized role in embryo development between fertilization and the 8‐cell stage at embryonic day (E) 2.5. S100a8 also has a second role in the maternal deciduum, where expression is associated with the vasculature from the E8.5 stage to the formation of mature placenta. Uterine natural killer cells that have a role in vascular remodelling colocalise with the S100a8 vascular expression in the metrial triangle. In inflammatory responses in peripheral tissues, S100a8 is a potent chemoattractant and also an anti‐oxidant. Both roles may be important in the developing placenta. Thus we highlight two new S100a9‐independent roles for S100a8 in early embryo development. Developmental Dynamics 240:2194–2203, 2011. © 2011 W... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137837 Wed, 17 Aug 2011 17:07:58 +0100 5137837 http://www.medworm.com/index.php?rid=5137836&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22711 AbstractAlthough many fetal birth defects, particularly those of the body wall and gut, are associated with abnormalities of the umbilical cord, the developmental relationship between these structures is largely obscure. Recently, genetic analysis of mid‐gestation mouse embryos revealed that defects in Hedgehog signaling led to omphalocoele, or failure of the body wall to close at the umbilical ring (Matsumaru et al. [ 2011] PLos One 6:e16260). However, systematic spatiotemporal localization of Hedgehog signaling in the allantois, or umbilical precursor tissue, and the surrounding regions has not been documented. Here, a combination of reagents, including the Ptc1:lacZ and Runx1:lacZ reporter mice, immunohistochemistry for Smoothened (Smo), Sonic Hedgehog (Shh), and Indian hedgehog (Ihh)... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137836 Wed, 17 Aug 2011 17:07:57 +0100 5137836 http://www.medworm.com/index.php?rid=5137834&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22712 AbstractMutated in Colorectal Cancer (MCC) encodes a multiple PSD‐95/Dlg/ZO‐1 (PDZ) domain‐containing protein implicated, as its name suggests, in the pathogenesis of human colon cancer. To date, however, what role, if any, MCC plays in normal tissue homeostasis and development remains unclear. In an effort to expand our understanding of MCC function and distribution, we examined the expression of the evolutionarily conserved mouse Mcc homolog between embryonic days (E) 6.5 and 12.5 using conventional whole‐mount in situ hybridization and two independent Mcc reporter alleles. Mcc is expressed in the posterior primitive streak during gastrulation and in diverse tissues of both mesodermal and endodermal origin. In addition, Mcc transcripts localize to the posterior neural tube and id... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137834 Wed, 17 Aug 2011 17:07:56 +0100 5137834 http://www.medworm.com/index.php?rid=5137833&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22715 AbstractMigration and differentiation of cranial neural crest cells are largely controlled by environmental cues, whereas pathfinding at the trunk level is dictated by cell‐autonomous molecular changes owing to early specification of the premigratory crest. Here, we investigated the migration and patterning of vagal neural crest cells. We show that (1) vagal neural crest cells exhibit some developmental bias, and (2) they take separate pathways to the heart and to the gut. Together these observations suggest that prior specification dictates initial pathway choice. However, when we challenged the vagal neural crest cells with different migratory environments, we observed that the behavior of the anterior vagal neural crest cells (somite‐level 1–3) exhibit considerable migratory plast... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137833 Wed, 17 Aug 2011 17:07:50 +0100 5137833 http://www.medworm.com/index.php?rid=5137832&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22714 AbstractCleft formation is the initial step of branching morphogenesis in many organs. We previously demonstrated that ROCK 1 regulates a nonmuscle myosin II‐dependent mechanochemical checkpoint to transition initiated clefts to progressing clefts in developing submandibular salivary glands. Here, we report that ROCK‐mediated integrin activation and subsequent formation of focal adhesion complexes comprise this mechanochemical checkpoint. Inhibition of ROCK1 and nonmuscle myosin II activity decreased integrin β1 activation in the cleft region and interfered with localization and activation of focal adhesion complex proteins, such as focal adhesion kinase (FAK). Inhibition of FAK activity also prevented cleft progression, by disrupting recruitment of the focal adhesion proteins talin a... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137832 Wed, 17 Aug 2011 17:07:48 +0100 5137832 http://www.medworm.com/index.php?rid=5137831&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22718 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137831 Wed, 17 Aug 2011 17:07:45 +0100 5137831 http://www.medworm.com/index.php?rid=5137830&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22700 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137830 Wed, 17 Aug 2011 17:07:44 +0100 5137830 http://www.medworm.com/index.php?rid=5137829&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22719 AbstractMid‐tailbud Ciona intestinalis embryo expressing GFP driven by the notochord specific cis‐regulatory module associated with the transcription factor Brachyury (green notochord cells). Embryos are counterstained with phalloidin (red) and DAPI (blue) to highlight F‐actin and nuclei, respectively. From José‐Edwards et al., Developmental Dynamics 240:1793–1805, 2011. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5137829 Wed, 17 Aug 2011 17:07:42 +0100 5137829 http://www.medworm.com/index.php?rid=5076374&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22699 AbstractSite‐specific recombinases (SSRs) are powerful tools for genome manipulation, used in diverse organisms including Drosophila melanogaster, mouse, Arabidopsis, zebrafish, and human cultured cells. The integrase from the bacteriophage ΦC31 belongs to the large serine family of integrases, and in contrast to other widely used SSRs such as Cre and Flp, recombination is directional and therefore irreversible. We have developed a vector system for recombinase‐mediated cassette exchange (RMCE) in the zebrafish, allowing swapping of the coding sequence in an integrated transgene. Utilizing codon‐optimized ΦC31 integrase RNA bearing the 3′UTR from the nanos1 gene, we replaced the egfp coding sequence of an integrated reporter transgene with mCherry coding sequence. Recombination w... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5076374 Sat, 30 Jul 2011 01:21:22 +0100 5076374 http://www.medworm.com/index.php?rid=5076375&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22708 AbstractHere we report that highly concentrated cationic lipid/helper lipid‐nucleic acid complexes (lipoplexes) can facilitate reproducible delivery of a variety of oligonucleotides and plasmids to chicken embryos or to mouse embryonic mesenchyme. Specifically, liposomes composed of N,N‐dioleyl‐N,N‐dimethylammonium chloride (DODAC)/1,2 dioleoyl glycero‐3‐phosphorylethanolamine (DOPE) prepared at 18‐mM concentrations produced high levels of transfection of exogenous genes in vivo and in vitro. Furthermore, we report sufficient uptake of plasmids expressing interference RNA to decrease expression of both exogenous and endogenous genes. The simplicity of preparation, implementation, and relatively low toxicity of this transfection reagent make it an attractive alternative for de... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5076375 Thu, 28 Jul 2011 23:00:00 +0100 5076375 http://www.medworm.com/index.php?rid=5061495&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22704 AbstractConditional mutations and transcription‐based reporters are important new tools for exploring the dynamic functions of biological pathways in vivo. While studying the role of the Wnt signaling pathway in cartilage, we observed that the β‐catenin‐dependent reporter TOPGAL was expressed in chondrocytes in which β‐catenin was conditionally inactivated using a Col2a1::cre driver. Here we show that in these embryos recombination is complete and full‐length β‐catenin protein is absent in chondrocytes. Although a null allele in this context, the recombined β‐catenin locus produces a stable transcript that encodes a truncated protein. The truncated protein alone fails to activate TOPFLASH, but strongly potentiates reporter activity in the presence of expressed β‐cateni... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5061495 Mon, 25 Jul 2011 19:25:18 +0100 5061495 http://www.medworm.com/index.php?rid=5061497&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22706 AbstractArteriovenous (AV) differentiation is a critical step during blood vessel formation and stabilization. Defects in arterial or venous fate lead to inappropriate fusion of vessels, resulting in damaging arteriovenous shunts. While many studies have unraveled the molecular underpinnings that drive AV fate, surprisingly, the spatiotemporal emergence of arteries and veins in mammalian embryos remains unknown. Here, we examine artery and vein specification and differentiation during vasculogenesis. We show that the first intraembryonic vessels formed are arteries, which differentiate in a stepwise manner. By contrast, veins emerge later, progressively forming after embryonic turning. In addition, we demonstrate that hemodynamic flow is not required for arterial specification, but is requ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5061497 Sun, 24 Jul 2011 23:00:00 +0100 5061497 http://www.medworm.com/index.php?rid=5061496&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22705 AbstractSpatial and temporal gene regulation relies on a combinatorial code of sequence‐specific transcription factors that must be integrated by the general transcriptional machinery. A key link between the two is the mediator complex, which consists of a core complex that reversibly associates with the accessory kinase module. We show here that genes activated by Notch signaling at the dorsal–ventral boundary of the Drosophila wing disc fall into three classes that are affected differently by the loss of kinase module subunits. One class requires all four kinase module subunits for activation, while the others require only Med12 and Med13, either for activation or for repression. These distinctions do not result from different requirements for the Notch coactivator Mastermind or the ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5061496 Sun, 24 Jul 2011 23:00:00 +0100 5061496 http://www.medworm.com/index.php?rid=5048301&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22701 In this study, we report isolation and initial characterization of all four PIAS genes from Xenopus laevis. The Xenopus PIAS genes are expressed throughout early development and have overlapping and distinct expression patterns, with, for example, high levels of PIAS2 in the notochord and strong expression of PIAS4 in the neural and neural crest derivatives. Overexpression of PIAS disrupts mesoderm induction and impairs body axis formation. PIAS proteins have differential ability to regulate signals from the growth factors activin, bone morphogenetic protein 4 (BMP4), and Wnt8. Our data suggest that Xenopus PIAS play important roles in mesodermal induction and patterning during early frog development. Developmental Dynamics, 2011. © 2011 Wiley‐Liss, Inc. (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5048301 Thu, 21 Jul 2011 23:46:06 +0100 5048301 http://www.medworm.com/index.php?rid=5048303&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22703 AbstractThe expression of seven members of the ADAM family was investigated by in situ hybridization in the developing feather buds of chicken. The expression profiles of the ADAMs in the cells and tissues of the feather buds differ from each other. ADAM9, ADAM10, and ADAM17 are expressed in the epidermis of the feather bud, whereas ADAM23 expression is restricted to the bud crest, with a distribution similar to that of sonic hedgehog. ADAM13 is not only expressed in the epidermis, but also in restricted regions of the dermis. Both ADAM12 and ADAM22 are expressed in the dermis of the feather bud, with an opposite mediolateral and anteroposterior polarity. Furthermore, the mRNAs of all investigated ADAMs show regional differences in their expression, for example, in the neck and in the root... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5048303 Tue, 19 Jul 2011 23:00:00 +0100 5048303 http://www.medworm.com/index.php?rid=5048302&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22702 AbstractAlthough the function of transforming growth factor beta2 (TGFβ2) in epithelial mesenchymal transition (EMT) is well studied, its role in valve remodeling remains to be fully explored. Here, we used histological, morphometric, immunohistochemical and molecular approaches and showed that significant dysregulation of major extracellular matrix (ECM) components contributed to valve remodeling defects in Tgfb2−/− embryos. The data indicated that cushion mesenchymal cell differentiation was impaired in Tgfb2−/− embryos. Hyaluronan and cartilage link protein‐1 (CRTL1) were increased in hyperplastic valves of Tgfb2−/− embryos, indicating increased expansion and diversification of cushion mesenchyme into the cartilage cell lineage during heart development. Finally, Western b... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5048302 Tue, 19 Jul 2011 23:00:00 +0100 5048302 http://www.medworm.com/index.php?rid=5026834&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22689 (Source: Developmental Dynamics) Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5026834 Thu, 14 Jul 2011 22:04:05 +0100 5026834 http://www.medworm.com/index.php?rid=5026833&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22688 AbstractIn 2006, Yamanaka's group announced they had discovered the proverbial “fountain of youth” for human cells, forever changing the field of stem cell research. After misexpressing within them a cocktail of four genes, adult somatic cells revert into an embryonic stem cell (ESC)‐like state. These so‐called induced pluripotent stem cells (iPSCs) can differentiate into a wide variety of cell types, seemingly bypassing the need for politically charged ESCs. However, iPSCs differ from ESCs in potentially deleterious ways, precluding their use in regenerative medicine. In this primer and adjoining discussion with iPSC biologists William Lowry, PhD, and Clive Svendsen, PhD, we explore these issues as well how iPSCs promise to contribute to the understanding of developmental biology ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5026833 Thu, 14 Jul 2011 22:04:01 +0100 5026833 http://www.medworm.com/index.php?rid=5026832&cid=s_33766_67_f&fid=33766&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdvdy.22693 AbstractThe synuclein family consists of three small intracellular proteins mainly expressed in neural tissues, and has been associated with human neurodegenerative diseases. We have examined the spatial and temporal expression patterns of three synuclein genes during embryogenesis of Xenopus laevis. The Xenopus synucleins were firstly expressed in the developing nervous system at the tail bud stages. At tadpole stages, Xenopus snca was expressed in the brain, branchial arch and somite, and sncbb signals were detected in entire brain and spinal cord. However, sncg was only expressed in the peripheral nervous system including trigeminal nerve and dorsal root ganglion. RT‐PCR indicated that expression of synucleins was up‐regulated at the end of neurulation, and then maintained at later ... Developmental Dynamics journals http://www.medworm.com/rss/comments.php?id=5026832 Thu, 14 Jul 2011 22:03:58 +0100 5026832