neuroD Induces Photoreceptor Cell Overproduction In Vivo and De Novo Generation In Vitro

摘要: The molecular mechanisms underlying the generation of various types cells in vertebrate retina are largely unknown. We investigated possibility that genes belonging to basic helix-loop-helix (bHLH) family transcriptional factors participate 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 expressed located at outer portion developing neuroepithelium, location where prospective photoreceptors reside. Misexpression neuroepithelium through replication-competent, transformation-deficient retroviruses produced a three, instead two, layers photoreceptor cells; number express visinin, marker for cone photoreceptors, increased over 50% compared control embryos misexpressing green fluorescent protein. No significant changes were observed other neurons, including those RA4 (ganglion cells), pax6 amacrine chx10 (bipolar cells). Retroviral-driven misexpression monolayer cultures pigment epithelium yielded de novo production no neurons detected. propose is important cell retina. © 1998 John Wiley & Sons, Inc. J Neurobiol 36: 485–496,