Involvement of SIP1 in positioning of somite boundaries in the mouse embryo

Dev Dyn. 2005 Oct;234(2):332-8. doi: 10.1002/dvdy.20546.

Abstract

Periodical production of somites provides an excellent model system for understanding genesis of metameric structures underlying embryonic development. This study reports production of somites with roughly half rostro-caudal length in homozygous Sip1 (Smad-interacting protein 1) knockout mouse embryos. This altered periodicity of somitogenesis is caused by the rostral expansion of the expression domain of genes involved in the maintenance of unsegmented state of paraxial mesoderm, e.g., Fgf8, Wnt3a, Dll3, and Tbx6. This is accompanied by the rostral extension of oscillatory gene expression such as L-fng, Hes7, and Dll1, and the rostrally shifted termination of Raldh2 expression that continues from the anterior embryonic side. The phenotype of Sip1-/- embryo introduces a new molecular component SIP1 in positioning of somite boundaries, and provides support for the current "clock and wavefront" model.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehyde Oxidoreductases / metabolism
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Embryo, Mammalian / metabolism*
  • Fibroblast Growth Factor 8 / metabolism
  • Gene Expression Regulation, Developmental*
  • Heterozygote
  • Homozygote
  • In Situ Hybridization
  • Intracellular Signaling Peptides and Proteins
  • Introns
  • Membrane Proteins / metabolism
  • Mesoderm / metabolism
  • Mice
  • Mice, Knockout
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology*
  • Oscillometry
  • Phenotype
  • Plasmids / metabolism
  • Somites / metabolism
  • T-Box Domain Proteins
  • Time Factors
  • Transcription Factors / metabolism
  • Wnt Proteins / metabolism
  • Wnt3 Protein
  • Wnt3A Protein

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • DLL3 protein, human
  • Fgf8 protein, mouse
  • Hes7 protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Sip1 protein, mouse
  • T-Box Domain Proteins
  • Tbx6 protein, mouse
  • Transcription Factors
  • WNT3A protein, human
  • Wnt Proteins
  • Wnt3 Protein
  • Wnt3A Protein
  • Wnt3a protein, mouse
  • Fibroblast Growth Factor 8
  • Aldehyde Oxidoreductases
  • RALDH2 protein, mouse