Genomic code for Sox2 binding uncovers its regulatory role in Six3 activation in the forebrain

Dev Biol. 2013 Sep 15;381(2):491-501. doi: 10.1016/j.ydbio.2013.06.016. Epub 2013 Jun 19.

Abstract

The SRY-related HMG box transcription factor Sox2 plays critical roles throughout embryogenesis. Haploinsufficiency for SOX2 results in human developmental defects including anophthalmia, microphthalmia and septo-optic dysplasia, a congenital forebrain defect. To understand how Sox2 plays a role in neurogenesis, we combined genomic and in vivo transgenic approaches to characterize genomic regions occupied by Sox2 in the developing forebrain. Six3, a homeobox gene associated with holoprosencephaly, a forebrain midline defect, was identified as a Sox2 transcriptional target. This study shows that Sox2 directly regulates a previously unidentified long-range forebrain enhancer to activate Six3 expression in the rostral diencephalon. Further biochemical and genetic evidences indicated a direct regulatory link between Sox2 and Six3 during forebrain development, providing a better understanding of a common molecular mechanism underlying these forebrain defects.

Keywords: ChIP Display; Forebrain; Mouse; Six3; Sox2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites
  • Conserved Sequence
  • Embryo, Mammalian / metabolism
  • Embryonic Development
  • Enhancer Elements, Genetic
  • Evolution, Molecular
  • Eye Proteins / genetics
  • Eye Proteins / metabolism*
  • Gene Expression Regulation, Developmental*
  • Hedgehog Proteins / genetics
  • Hedgehog Proteins / metabolism
  • Homeobox Protein SIX3
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Mice
  • Mice, Transgenic
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neural Plate / embryology
  • Neural Plate / metabolism
  • Prosencephalon / cytology
  • Prosencephalon / embryology
  • Prosencephalon / metabolism*
  • Protein Binding
  • SOXB1 Transcription Factors / genetics*
  • SOXB1 Transcription Factors / metabolism
  • Transcriptional Activation

Substances

  • Eye Proteins
  • Hedgehog Proteins
  • Homeodomain Proteins
  • Nerve Tissue Proteins
  • SOXB1 Transcription Factors
  • Shh protein, mouse
  • Sox2 protein, mouse