Interest in developmental interactions involving the notochord and perinotochordal sheath led to a comparative investigation of these structures in three mouse mutants. Alcian blue or periodic acid-Schiff staining of 9 1/2-13 days' gestational age embryos revealed a supernumerary notochordal-like mass of cells or a deflected notochord in association with duplication of the neural tube in mice o...

We compared the transcriptome in the developing notochord of Xenopus laevis embryos with that of other embryonic regions. A coordinated and intense activation of a large set of secretory pathway genes was observed in the notochord, but not in notochord precursors in the axial mesoderm at early gastrula stage. The genes encoding Xbp1 and Creb3l2 were also activated in the notochord. These two tr...

The notochord is required for body plan patterning in vertebrates, and defects in notochord development during embryogenesis can lead to diseases affecting the adult. It is therefore important to elucidate the gene regulatory mechanism underlying notochord formation. In this study, we cloned the zebrafish zinc finger 219-like (ZNF219L) based on mammalian ZNF219, which contains nine C2H2-type zi...

somitogenesis clock was evaluated by assessing the rate and number of somites formed and gene expression alterations upon notochord ablation. Chick embryo explants were cultured for different time periods with or without notochord. We found that notochord removal delays somite formation from the undetermined PSM and alters both clock and determination front gene expression. We show that Shh is ...

somitogenesis clock was evaluated by assessing the rate and number of somites formed and gene expression alterations upon notochord ablation. Chick embryo explants were cultured for different time periods with or without notochord. We found that notochord removal delays somite formation from the undetermined PSM and alters both clock and determination front gene expression. We show that Shh is ...

The notochord is critical for the normal development of vertebrate embryos. It serves both as the major skeletal element of the embryo and as a signaling source for the establishment of pattern within the neurectoderm, the paraxial mesoderm and other tissues. In a large-scale systematic screen of mutations affecting embryogenesis in zebrafish we identified 65 mutations that fall into 29 complem...

Cell fate decisions in early embryonic cells are controlled by interactions among developmental regulatory genes. Zebrafish floating head mutants lack a notochord; instead, muscle forms under the neural tube. As shown previously, axial mesoderm in floating head mutant gastrulae fails to maintain expression of notochord genes and instead expresses muscle genes. Zebrafish spadetail mutant gastrul...

Patterning of the ventral half of the neural tube results from the inductive influence of the notochord and of the floor plate. We have studied here the effect of an ectopically grafted notochord on the development of the dorsalmost part of the neural tube i.e. roof plate and alar plates. We show that at their early stages, dorsal genes are repressed by the dorsal graft of a notochord, as shown...

somitogenesis clock was evaluated by assessing the rate and number of somites formed and gene expression alterations upon notochord ablation. Chick embryo explants were cultured for different time periods with or without notochord. We found that notochord removal delays somite formation from the undetermined PSM and alters both clock and determination front gene expression. We show that Shh is ...

The expression of a winged-helix transcription factor, Foxa2/HNF3beta, is essential for development of the node and the notochord. We examined the node/notochord enhancer of mouse Foxa2 for sequence motifs conserved across vertebrate species. We cloned Foxa2 genes from chicken and fish, and identified the respective node/notochord enhancers that were active in transgenic mouse embryos. Comparis...