neuroD induces photoreceptor cell overproduction in vivo and de novo generation in vitro

J Neurobiol. 1998 Sep 15;36(4):485-96.


The molecular mechanisms underlying the generation of the various types of cells in the vertebrate retina are largely unknown. We investigated the possibility that genes belonging to the basic helix-loop-helix (bHLH) family of transcriptional factors participate in cell-type specification during retinal neurogenesis. Chick neuroD was isolated from an embryonic cDNA library and its deduced amino acid sequence showed 75% identity with mouse neuroD. In situ hybridization showed that neuroD was expressed in cells located at the outer portion of the developing retinal neuroepithelium, the location where prospective photoreceptors reside. Misexpression of neuroD in retinal neuroepithelium through replication-competent, transformation-deficient retroviruses produced a retina with three, instead of two, layers of photoreceptor cells; the number of cells that express visinin, a marker for cone photoreceptors, increased over 50% compared to control embryos misexpressing the green fluorescent protein. No significant changes were observed in the number of other retinal neurons, including those that express RA4 (ganglion cells), pax6 (ganglion cells and amacrine cells), and chx10 (bipolar cells). Retroviral-driven misexpression of neuroD in monolayer cultures of retinal pigment epithelium yielded de novo production of photoreceptor cells with no other types of retinal neurons detected. We propose that neuroD is important for photoreceptor cell production in the vertebrate retina.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors
  • Cells, Cultured
  • Chick Embryo
  • Cloning, Molecular
  • Green Fluorescent Proteins
  • Helix-Loop-Helix Motifs
  • In Situ Hybridization
  • Luminescent Proteins / biosynthesis
  • Mice
  • Molecular Sequence Data
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / pharmacology*
  • Photoreceptor Cells, Invertebrate / metabolism*
  • Retina / cytology
  • Retroviridae / metabolism


  • Basic Helix-Loop-Helix Transcription Factors
  • Luminescent Proteins
  • Nerve Tissue Proteins
  • Green Fluorescent Proteins
  • NeuroD protein

Associated data

  • GENBANK/AF060885