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Early Vertebrate Development (early + vertebrate_development)
Selected AbstractsIn vitro organogenesis of pancreas in Xenopus laevis dorsal lips treated with retinoic acidDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 2 2000Naomi Moriya Dorsal lips of Xenopus laevis may differentiate into pancreas after treatment with retinoic acid in vitro. The dorsal lip region is fated to be dorsal mesoderm and anterior endoderm. Dorsal lip cells isolated from stage 10 early gastrula differentiate into tissues such as notochord, muscle and pharynx. However, in the present study, dorsal lips treated with 10,4M retinoic acid for 3 h differentiated into pancreas-like structures accompanied by notochord and thick endodermal epithelium. Sections of the explants showed that some cells gathered and formed an acinus-like structure as observed under microscopes. In addition to the morphological changes, expressions of the pancreas-specific molecular markers, XlHbox8 and insulin, were induced in retinoic acid-treated dorsal lip explants. Therefore, it is suggested that retinoic acid may induce the dorsal lip cells to differentiate into a functional pancreas. However, continuous treatment with retinoic acid did not induce pancreas differentiation at any concentration. Dorsal lips treated with retinoic acid within 5 h after isolation differentiated into pancreas-like cells, while those treated after 15 h or more did not. The present study provided a suitable test system for analyzing pancreas differentiation in early vertebrate development. [source] Beyond early development: Xenopus as an emerging model for the study of regenerative mechanismsDEVELOPMENTAL DYNAMICS, Issue 6 2009Caroline W. Beck Abstract While Xenopus is a well-known model system for early vertebrate development, in recent years, it has also emerged as a leading model for regeneration research. As an anuran amphibian, Xenopus laevis can regenerate the larval tail and limb by means of the formation of a proliferating blastema, the lens of the eye by transdifferentiation of nearby tissues, and also exhibits a partial regeneration of the postmetamorphic froglet forelimb. With the availability of inducible transgenic techniques for Xenopus, recent experiments are beginning to address the functional role of genes in the process of regeneration. The use of soluble inhibitors has also been very successful in this model. Using the more traditional advantages of Xenopus, others are providing important lineage data on the origin of the cells that make up the tissues of the regenerate. Finally, transcriptome analyses of regenerating tissues seek to identify the genes and cellular processes that enable successful regeneration. Developmental Dynamics 238:1226,1248, 2009. © 2009 Wiley-Liss, Inc. [source] A green to red photoconvertible protein as an analyzing tool for early vertebrate developmentDEVELOPMENTAL DYNAMICS, Issue 2 2007Stephan A. Wacker Abstract Lineage labeling is one of the most important techniques in developmental biology. Most recently, a set of photoactivatable fluorescent proteins originating from marine cnidarians became available. Here, we introduce the application of the green to red photoconvertible protein EosFP as a novel technique to analyze early vertebrate development. Both injection of EosFP mRNA and purified, recombinant EosFP followed by a light-driven green to red conversion allow lineage labeling in virtually any temporal and spatial dimension during embryonic development for at least 2 weeks. Specific staining of cells from nonsurface layers is greatly facilitated by light-driven conversion of EosFP compared with traditional methods. Therefore, green to red photoactivatable proteins promise to be a powerful tool with the potential to satisfy the increasing demand for methods enabling detailed phenotypical analyses after manipulations of morphogenetic events, gene expression, or signal transduction. Developmental Dynamics 236:473,480, 2007. © 2006 Wiley-Liss, Inc. [source] | ||||||||||