Pax-6, Prox 1, and Chx10 homeobox gene expression correlates with phenotypic fate of retinal precursor cells

Invest Ophthalmol Vis Sci. 1997 Jun;38(7):1293-303.


Purpose: To study the expression patterns of the homeobox genes Pax-6, Prox 1, and Chx10 during chick retinal development in vivo and in vitro.

Methods: Sections of paraformaldehyde-fixed, paraffin-embedded eyes were obtained at a range of developmental stages. In situ hybridization was carried out on tissue sections using digoxigenin-labeled sense and antisense RNA probes that recognize chicken Pax-6 and Prox 1 (whose sequences were already available), and chicken Chx10 (which was cloned and sequenced as part of this study). Selected developmental stages were also studied by immunocytochemistry with antibodies against Pax-6 and Prox 1, and by Northern blot analysis using 32P-labeled probes.

Results: Until embryonic day (ED) 5, in situ hybridization shows widespread, diffuse distribution of all three genes. Between ED 6 and ED 8, however, they acquire distinct, topographically specific patterns of expression. The Prox 1 signal is predominantly expressed in the prospective horizontal cell layer of the neuroepithelium, decreases vitreally, and is absent from ganglion cells and the prospective photoreceptor layer. Pax-6 is strongly expressed only in the prospective ganglion-cell and amacrine-cell regions at the same stages, and is not detected in prospective photoreceptors. Chx10 expression becomes concentrated in the future bipolar-cell region of the inner nuclear layer. Similar patterns are maintained by ED 15 through ED 18, after cell differentiation has taken place. Pax-6 and Prox 1 immunoreactive materials showed nuclear localization and a pattern of laminar distribution equivalent to that seen by in situ hybridization.

Conclusions: These results suggest that the differentiated fate of retinal precursor cells may be influenced by Pax-6, Prox 1, or Chx10, this hypothesis is now being tested using dissociated chick embryo retinal cell cultures.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Avian Proteins*
  • Base Sequence
  • Blotting, Northern
  • Cell Differentiation
  • Cell Lineage / physiology*
  • Chick Embryo
  • DNA-Binding Proteins / biosynthesis*
  • DNA-Binding Proteins / genetics
  • Eye Proteins
  • Gene Expression Regulation, Developmental / physiology
  • Genes, Homeobox*
  • Homeodomain Proteins / biosynthesis*
  • Homeodomain Proteins / genetics
  • In Situ Hybridization
  • Mice
  • Molecular Sequence Data
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Phenotype
  • RNA Probes
  • Rabbits
  • Repressor Proteins
  • Retina / embryology
  • Retina / metabolism*
  • Sequence Homology, Amino Acid
  • Stem Cells / physiology
  • Transcription Factors / biosynthesis*
  • Transcription Factors / genetics
  • Tumor Suppressor Proteins


  • Avian Proteins
  • DNA-Binding Proteins
  • Eye Proteins
  • Homeodomain Proteins
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Pax6 protein, mouse
  • RNA Probes
  • Repressor Proteins
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Vsx2 protein, mouse
  • prospero-related homeobox 1 protein