vhnf1 and Fgf signals synergize to specify rhombomere identity in the zebrafish hindbrain

Development. 2003 Aug;130(16):3821-9. doi: 10.1242/dev.00572.

Abstract

Vertebrate hindbrain segmentation is a highly conserved process but the mechanism of rhombomere determination is not well understood. Recent work in the zebrafish has shown a requirement for fibroblast growth factor (Fgf) signaling and for the transcription factor variant hepatocyte nuclear factor 1 (vhnf1) in specification of rhombomeres 5 and 6 (r5+r6). We show here that vhnf1 functions in two ways to subdivide the zebrafish caudal hindbrain domain (r4-r7) into individual rhombomeres. First, vhnf1 promotes r5+r6 identity through an obligate synergy with Fgf signals to activate valentino and krox20 expression. Second, vhnf1 functions independently of Fgf signals to repress hoxb1a expression. Although vhnf1 is expressed in a broad posterior domain during gastrulation, it promotes the specification of individual rhombomeres. This is achieved in part because vhnf1 gives cellular competence to respond to Fgf signals in a caudal hindbrain-specific manner.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Epistasis, Genetic
  • Fibroblast Growth Factors / genetics
  • Fibroblast Growth Factors / metabolism*
  • Gene Expression Regulation, Developmental*
  • Hepatocyte Nuclear Factor 1-beta
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • In Situ Hybridization
  • MafB Transcription Factor
  • Morphogenesis
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Oligonucleotides, Antisense / genetics
  • Oligonucleotides, Antisense / metabolism
  • Rhombencephalon / anatomy & histology
  • Rhombencephalon / embryology*
  • Rhombencephalon / physiology
  • Signal Transduction / physiology*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Zebrafish / embryology*
  • Zebrafish / genetics
  • Zebrafish / metabolism
  • Zebrafish Proteins*

Substances

  • DNA-Binding Proteins
  • HOXB1 homeodomain protein
  • Hnf1b protein, rat
  • Homeodomain Proteins
  • MafB Transcription Factor
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • Oligonucleotides, Antisense
  • Transcription Factors
  • Zebrafish Proteins
  • mafb protein, zebrafish
  • Hepatocyte Nuclear Factor 1-beta
  • Fibroblast Growth Factors