Distinct expression of two foxg1 paralogues in zebrafish

Gene Expr Patterns. 2009 Jun;9(5):266-72. doi: 10.1016/j.gep.2009.04.001. Epub 2009 Apr 18.


The forkhead proteins (Fox) act as transcription factors in many biological processes in a wide range of species. One member of this superfamily, Foxg1, has essential roles in the development of eyes, telencephalon, ears and olfactory system. Zebrafish foxg1 has been reported to have similar roles as the mouse orthologue Foxg1. However, no data has been reported about possible zebrafish foxg1 paralogues. In this study we identified one zebrafish foxg1 paralogue by enhancer trapping, which we designate foxg1b. A more diverged paralogue, foxg1c, was identified by homology searches. Sequence comparisons indicate that both foxg1b and foxg1c are less related to mouse than the previously characterized foxg1. We report that foxg1b is expressed in a regionally restricted pattern within the developing eye, mainly in the dorsal-nasal retina, which is similar to the retinal expression of mouse Foxg1. By contrast, foxg1c is only expressed transiently in the eyes and forebrain between 14 and 20h post-fertilization, while expression was detected exclusively in the developing inner ear at later stages. Our results suggest that foxg1b and foxg1c have undergone expression pattern divergence during evolution that has resulted in functional specialization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Animals, Genetically Modified
  • Ear / embryology
  • Eye / embryology
  • Eye / metabolism
  • Forkhead Transcription Factors / genetics*
  • Gene Expression Profiling*
  • Gene Expression Regulation, Developmental*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • In Situ Hybridization
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Prosencephalon / embryology
  • Prosencephalon / metabolism
  • Protein Isoforms / genetics
  • Retina / embryology
  • Retina / metabolism
  • Sequence Homology, Amino Acid
  • Zebrafish / embryology
  • Zebrafish / genetics*
  • Zebrafish Proteins / genetics*


  • Forkhead Transcription Factors
  • Protein Isoforms
  • Zebrafish Proteins
  • foxg1a protein, zebrafish
  • Green Fluorescent Proteins