Pax6 induces ectopic eyes in a vertebrate

Development. 1999 Oct;126(19):4213-22. doi: 10.1242/dev.126.19.4213.


We report here that misexpression of the transcription factor Pax6 in the vertebrate Xenopus laevis leads to the formation of differentiated ectopic eyes. Multiple molecular markers indicated the presence of mature lens fiber cells, ganglion cells, Müller cells, photoreceptors and retinal pigment epithelial cells in a spatial arrangement similar to that of endogenous eyes. Lineage tracing experiments showed that lens, retina and retinal pigment epithelium arose as a consequence of the cell-autonomous function of Pax6. These experiments also reveal that the cell autonomous activity of misexpressed Pax6 causes the ectopic expression of a number of genes including Rx, Otx2, Six3 and endogenous Pax6, each of which has been implicated in eye development. The formation of ectopic and endogenous eyes could be suppressed by coexpression of a dominant-negative form of Pax6. These data show that in vertebrates, as in the invertebrate Drosophila melanogaster, Pax6 is both necessary and sufficient to trigger the cascade of events required for eye formation.

Publication types

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

MeSH terms

  • Animals
  • Choristoma*
  • Cloning, Molecular
  • DNA-Binding Proteins / physiology*
  • Embryo, Nonmammalian / metabolism
  • Eye Abnormalities / genetics
  • Eye Proteins
  • Eye* / anatomy & histology
  • Eye* / embryology
  • Gene Expression Regulation, Developmental
  • Genes, Dominant
  • Homeodomain Proteins*
  • In Situ Hybridization
  • Lens, Crystalline / anatomy & histology
  • Lens, Crystalline / embryology
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Phenotype
  • Repressor Proteins
  • Retina / anatomy & histology
  • Retina / embryology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Xenopus laevis / embryology*
  • Xenopus laevis / genetics


  • DNA-Binding Proteins
  • Eye Proteins
  • Homeodomain Proteins
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Repressor Proteins

Associated data

  • GENBANK/AF175342