Genome-wide characterization of Foxa2 targets reveals upregulation of floor plate genes and repression of ventrolateral genes in midbrain dopaminergic progenitors

Development. 2012 Jul;139(14):2625-34. doi: 10.1242/dev.081034. Epub 2012 Jun 13.

Abstract

The transcription factors Foxa1 and Foxa2 promote the specification of midbrain dopaminergic (mDA) neurons and the floor plate. Whether their role is direct has remained unclear as they also regulate the expression of Shh, which has similar roles. We characterized the Foxa2 cis-regulatory network by chromatin immunoprecipitation followed by high-throughput sequencing of mDA progenitors. This identified 9160 high-quality Foxa2 binding sites associated with 5409 genes, providing mechanistic insights into Foxa2-mediated positive and negative regulatory events. Foxa2 regulates directly and positively key determinants of mDA neurons, including Lmx1a, Lmx1b, Msx1 and Ferd3l, while negatively inhibiting transcription factors expressed in ventrolateral midbrain such as Helt, Tle4, Otx1, Sox1 and Tal2. Furthermore, Foxa2 negatively regulates extrinsic and intrinsic components of the Shh signaling pathway, possibly by binding to the same enhancer regions of co-regulated genes as Gli1. Foxa2 also regulates the expression of floor plate factors that control axon trajectories around the midline of the embryo, thereby contributing to the axon guidance function of the floor plate. Finally, this study identified multiple Foxa2-regulated enhancers that are active in the floor plate of the midbrain or along the length of the embryo in mouse and chick. This work represents the first comprehensive characterization of Foxa2 targets in mDA progenitors and provides a framework for elaborating gene regulatory networks in a functionally important progenitor population.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Cell Line
  • Chromatin Immunoprecipitation
  • Dopaminergic Neurons / metabolism*
  • Electroporation
  • Genotype
  • Hepatocyte Nuclear Factor 3-beta / genetics
  • Hepatocyte Nuclear Factor 3-beta / metabolism*
  • Immunohistochemistry
  • In Situ Hybridization
  • LIM-Homeodomain Proteins / genetics
  • LIM-Homeodomain Proteins / metabolism
  • MSX1 Transcription Factor / genetics
  • MSX1 Transcription Factor / metabolism
  • Mesencephalon / cytology*
  • Mice
  • Mice, Mutant Strains
  • Mice, Transgenic
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Protein Binding
  • Repressor Proteins
  • SOXB1 Transcription Factors / genetics
  • SOXB1 Transcription Factors / metabolism
  • Stem Cells / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Ferd3l protein, mouse
  • Foxa2 protein, mouse
  • LIM homeobox transcription factor 1 beta
  • LIM-Homeodomain Proteins
  • Lmx1a protein, mouse
  • MSX1 Transcription Factor
  • Msx1 protein, mouse
  • Neoplasm Proteins
  • Nerve Tissue Proteins
  • Repressor Proteins
  • SOXB1 Transcription Factors
  • Sox1 protein, mouse
  • Tal2 protein, mouse
  • Transcription Factors
  • Hepatocyte Nuclear Factor 3-beta