T promoter activity in the absence of functional T protein during axis formation and elongation in the mouse

Dev Biol. 1997 Sep 15;189(2):161-73. doi: 10.1006/dbio.1997.8661.

Abstract

The T (Brachyury) gene, which encodes a transcription factor, is involved in the formation of posterior mesoderm. Although studies in Xenopus have shown that T gene expression is responsive to mesoderm inducing factors and furthermore suggest the existence of an autoregulatory loop involving T itself, eFGF, and the FGF receptor, little is known about the regulation of T expression in the mouse. We report here that in the mouse the expression of fgf-4, the putative homologue of Xenopus efgf, is not dependent on the presence of T protein during the first 48 hr of gastrulation. Furthermore, we address the question of autoregulation using a chimeric approach. Introduction of a T promoter-lacZ construct into T/T ES cells results in T promoter activity in the primitive streak and tail bud in the absence of functional T protein. Therefore, we suggest that a direct FGF and T autoregulatory loop is unlikely to operate during gastrulation and axis elongation in the mouse.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Chimera / genetics
  • Chimera / physiology
  • Clone Cells
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / physiology
  • Embryonic and Fetal Development / genetics*
  • Embryonic and Fetal Development / physiology
  • Fetal Proteins / genetics*
  • Fetal Proteins / physiology
  • Fibroblast Growth Factor 4
  • Fibroblast Growth Factors / genetics
  • Gastrula / physiology
  • Gene Expression Regulation, Developmental / physiology*
  • Lac Operon
  • Mesoderm / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred CBA
  • Promoter Regions, Genetic*
  • Proto-Oncogene Proteins / genetics
  • T-Box Domain Proteins*
  • Transcription Factors / genetics*
  • Transcription Factors / physiology

Substances

  • DNA-Binding Proteins
  • Fetal Proteins
  • Fgf4 protein, mouse
  • Fibroblast Growth Factor 4
  • Proto-Oncogene Proteins
  • T-Box Domain Proteins
  • Transcription Factors
  • Fibroblast Growth Factors
  • Brachyury protein