Search results for "Somitogenesis"

2018

During gastrulation, embryonic cells become specified into distinct germ layers. In mouse, this continues throughout somitogenesis from a population of bipotent stem cells called neuromesodermal progenitors (NMps). However, the degree of self-renewal associated with NMps in the fast-developing zebrafish embryo is unclear. With a genetic clone tracing method, we labelled early embryonic progenitors and find a strong clonal similarity between spinal cord and mesoderm tissues. We followed individual cell lineages by light-sheet imaging, revealing a common neuromesodermal lineage contribution to a subset of spinal cord tissue across the anterior-posterior body axis. An initial population subdiv…

09-P102 Somitogenesis and development of primary motor neurons: The role of the homeobox uncx4.1

2009

The gene uncx4.1 is a paired-type homeobox transcription factor, expressed during zebrafish embryonic development in branchial arches, somites, CNS and pronephric ducts. In particular, the expression at the somite level is detectable from 5ss stage and becomes progressively posteriorly and ventrally restricted to the presumptive myoblast cells in later stages. Interestingly, the progressive restriction of uncx4.1 activity anticipates and accompanies the appearance of the first outgrowing primary motor axons. Indeed, after uncx4.1 expression is not detected anymore in medial somitic cells, a ventrally projecting CaP motor axons emerge from the ventro-lateral spinal cord. In relation with mus…

Neuromesodermal Progenitors are a Conserved Source of Spinal Cord with Divergent Growth Dynamics

2018

AbstractDuring gastrulation, embryonic cells become specified into distinct germ layers. In mouse, this continues throughout somitogenesis from a population of bipotent stem cells called neuromesodermal progenitors (NMps). However, the degree self-renewal is associated with NMps in the fast-developing zebrafish embryo is unclear. With a genetic clone tracing method, we labelled early embryonic progenitors and find a strong clonal similarity between spinal cord and mesoderm tissues. We then followed individual cell lineages by light-sheet imaging and reveal a common neuromesodermal lineage contribution to a subset of spinal cord tissue across the anterior-posterior body axis. An initial popu…

α5β1 integrin-mediated adhesion to fibronectin is required for axis elongation and somitogenesis in mice.

2011

The arginine-glycine-aspartate (RGD) motif in fibronectin (FN) represents the major binding site for α5β1 and αvβ3 integrins. Mice lacking a functional RGD motif in FN (FN(RGE/RGE)) or α5 integrin develop identical phenotypes characterized by embryonic lethality and a severely shortened posterior trunk with kinked neural tubes. Here we show that the FN(RGE/RGE) embryos arrest both segmentation and axis elongation. The arrest is evident at about E9.0, corresponding to a stage when gastrulation ceases and the tail bud-derived presomitic mesoderm (PSM) induces α5 integrin expression and assumes axis elongation. At this stage cells of the posterior part of the PSM in wild type embryos are tight…

Expression analysis of jagged genes in zebrafish embryos

2005

The interaction of transmembrane Delta and Jagged/Serrate ligands with Notch receptors on neighboring cells is critically involved in cell specification during development. In zebrafish, the early expression of delta but not of jagged genes has been investigated in some detail. We have analyzed the sequence and embryonic expression pattern of the three zebrafish genes jagged1a, jagged1b, and jagged2. These genes, whose transcripts are detectable by in situ hybridization from early somitogenesis, are widely and dynamically expressed in embryos. Coexpression is limited, however, to the notochord and lens (jagged1a and jagged1b) and to the otic vesicle and pronephros (jagged1b and jagged2). Co…