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Characterization of zebrafish olig1 and olig3 genes
No full textCharacterization of zebrafish olig1 and olig3 gene
Bmp2b and Chordin regulate endoderm patterning in zebrafish
No full textBmp2b and Chordin regulate endoderm patterning in zebrafis
Dorsoventral signals Bmp2b and Chordin regulate endoderm patterning in zebrafish
No full textDorsoventral signals Bmp2b and Chordin regulate endoderm patterning in zebrafis
BMP signalling regulates anteroposterior endoderm patterning in zebrafish
No full textIn vertebrates, the embryonic dorsoventral asymmetry is regulated by the bone morphogenetic proteins (Bmp) activity gradient. In the present study, we have used dorsalized swirl (bmp2b) and ventralized chordino (chordin) zebrafish mutants to investigate the effects of dorsoventral signalling on endoderm patterning and on the differentiation and positioning of its derivatives. Alterations of dorsoventral Bmp signalling do not perturb the induction of endodermal precursors, as shown by normal amounts of cells expressing cas and sox17 in swirl and chordino gastrulae, but affect dramatically the expression pattern of her5, a regulator of endoderm anteroposterior patterning in zebrafish. In particular, increased levels of Bmp signalling in chordino gastrulae are associated with a markedly reduced her5 expression domain, that may be abolished by injecting bmp2b mRNA. Conversely, in swirl mutants, lacking Bmp2b, the her5 expression domain is expanded. Thus, a gradient of Bmp2b signalling defines the extension of the her5 expression domain at gastrulation and the allocation of anterior endodermal precursors. A balanced Bmp2b signalling is also required for the normal development of the pancreas, as shown by the sharp reduction of the pancreatic primordium in swirl embryos and its expansion in chordino mutants. In the latter, at 3 days post-fertilization, the increased Bmp signalling does not compromise the endocrine/exocrine pancreas compartmentalization, but the right/left positioning of the pancreas and liver is randomized. Our results suggest that by regulating the expression of her5, the Bmp2b/Chordin gradient directs the anteroposterior patterning of endoderm in zebrafish embryos
olig3 establishes the neural plate boundary of the trunk and is necessary for the development of the dorsal spinal cord
No full textolig3 establishes the neural plate boundary of the trunk and is necessary for the development of the dorsal spinal cor
Analysis of glial cell formation/dysfunction in zebrafish embryos
No full textAnalysis of glial cell formation/dysfunction in zebrafish embryo
The basic helix-loop-helix olig3 establishes the neural plate boundary of the trunk and is necessary for development of the dorsal spinal cord
Full text linkolig genes encode a previously unrecognized group of vertebrate-specific basic helix-loop-helix transcription factors. As shown in mice, chickens, and zebrafish, two members of this group, olig1 and olig2, are involved in the differentiation of motoneurons and oligodendrocytes, but nothing is known about the role of the third member, olig3. Here, we show that olig3 plays an essential role in the establishment of the neural crest-lateral neural plate boundary. In zebrafish embryos, morpholino-induced olig3 inactivation dramatically increases the number of neural crest cells, but lateral neural plate fates (interneurons and astrocytes) are missing. Zebrafish swirl mutants that have impaired bone morphogenetic protein signaling and lack neural crest cells display an expanded olig3 expression domain. Moreover, olig3 is up-regulated in mindbomb mutants lacking the neural crest because of an impaired notch signaling, and olig3 repression in such mutants rescues the neural crest. In addition, olig3 regulates ngn1 and deltaA expression in interneuron precursors. Our results indicate that olig3 has an essential proneural activity in the dorsal spinal cord and cooperates with the Delta/Notch regulatory loop to establish the boundary between the neural crest and the lateral neural plate. Thus, a proper regulation of the olig gene family is essential for the formation of three cell types (oligodendrocytes, astrocytes, and neural crest) that are unique to vertebrates
The bHLH transcription factor Olig3 co-operates with Notch signalling to establish the trunk neural crest / lateral neural plate boundary
No full textThe bHLH transcription factor Olig3 co-operates with Notch signalling to establish the trunk neural crest / lateral neural plate boundar
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