Genome-wide view of cell fate specification: ladybird acts at multiple levels during diversification of muscle and heart precursors

Genes Dev. 2007 Dec 1;21(23):3163-80. doi: 10.1101/gad.437307.

Abstract

Correct diversification of cell types during development ensures the formation of functional organs. The evolutionarily conserved homeobox genes from ladybird/Lbx family were found to act as cell identity genes in a number of embryonic tissues. A prior genetic analysis showed that during Drosophila muscle and heart development ladybird is required for the specification of a subset of muscular and cardiac precursors. To learn how ladybird genes exert their cell identity functions we performed muscle and heart-targeted genome-wide transcriptional profiling and a chromatin immunoprecipitation (ChIP)-on-chip search for direct Ladybird targets. Our data reveal that ladybird not only contributes to the combinatorial code of transcription factors specifying the identity of muscle and cardiac precursors, but also regulates a large number of genes involved in setting cell shape, adhesion, and motility. Among direct ladybird targets, we identified bric-a-brac 2 gene as a new component of identity code and inflated encoding alphaPS2-integrin playing a pivotal role in cell-cell interactions. Unexpectedly, ladybird also contributes to the regulation of terminal differentiation genes encoding structural muscle proteins or contributing to muscle contractility. Thus, the identity gene-governed diversification of cell types is a multistep process involving the transcriptional control of genes determining both morphological and functional properties of cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Cell Adhesion / genetics
  • Cell Differentiation / genetics
  • Cell Fusion
  • Cell Movement / genetics
  • Chromatin Immunoprecipitation
  • Drosophila / cytology*
  • Drosophila / embryology
  • Drosophila / genetics*
  • Gene Expression Profiling
  • Gene Expression Regulation, Developmental
  • Gene Targeting
  • Genes, Homeobox*
  • Genes, Insect*
  • Genome, Insect
  • Models, Biological
  • Myoblasts / cytology*
  • Myoblasts, Cardiac / cytology*
  • RNA Interference