Development of chick axial mesoderm: Specification of prechordal mesoderm by anterior endoderm-derived TGFβ family signalling

Christine Vesque, Simon Ellis, Anne Lee, Marika Szabo, Paul Thomas, Rosa Beddington, Marysia Placzek

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Two populations of axial mesoderm cells can be recognised in the chick embryo, posterior notochord and anterior prechordal mesoderm. We have examined the cellular and molecular events that govern the specification of prechordal mesoderm. We report that notochord and prechordal mesoderm cells are intermingled and share expression of many markers as they initially extend out of Hensen's node. In vitro culture studies, together with in vivo grafting experiments, reveal that early extending axial mesoderm cells are labile and that their character may be defined subsequently through signals that derive from anterior endodermal tissues. Anterior endoderm elicits aspects of prechordal mesoderm identity in extending axial mesoderm by repressing notochord characteristics, briefly maintaining gsc expression and inducing BMP7 expression. Together these experiments suggest that, in vivo, signalling by anterior endoderm may determine the extent of prechordal mesoderm. The transforming growth factor β (TGFβ) superfamily members BMP2, BMP4, BMP7 and activin, all of which are transiently expressed in anterior endoderm mimic distinct aspects of its patterning actions. Together our results suggest that anterior endoderm-derived TGFβs may specify prechordal mesoderm character in chick axial mesoderm.

Original languageEnglish
Pages (from-to)2795-2809
Number of pages15
JournalDevelopment
Volume127
Issue number13
Publication statusPublished - 1 Jul 2000
Externally publishedYes

Keywords

  • Activin
  • Anterior endoderm
  • BMP
  • Chick
  • Hypoblast
  • Notochord
  • Prechordal mesoderm

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology

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