The nuclear receptor transcription factor, retinoid-related orphan receptor β, regulates retinal progenitor proliferation

Abstract

We examined the role of retinoid-related orphan receptor (ROR) β, a member of the nuclear receptor family of transcription factors, in retinal neurogenesis. In situ hybridization studies showed that ROR β is expressed in retinal progenitor cells in the embryonic rat retina. Further studies demonstrated that ROR β colocalizes with Chx10, a transcription factor thought to influence retinal progenitor proliferation (Burmeister, M., Novak, J., Liang, M-Y., Basu, S., Ploder, L., Hawes, N.L. Vidgen, D., Hoover, F., Goldman, D., Kalnins, V.I., Roderick, T.H., Taylor, B.A., Hankin, M.H. and McInnes, R.R., 1996. Ocular retardation mouse caused by Chx10 homeobox null allele: impaired retinal progenitor proliferation and bipolar cell differentiation. Nat. Genet. 12, 376–383). Northern analysis reveals that ROR β expression is dramatically decreased in the ocular retardation J mutant, which possesses a defect in the Chx10 gene. Overexpression of ROR β in retinal progenitors by biolistic transfection results in an increase in the number of large cell clones. These data support a role for ROR β in regulating retinal progenitor proliferation, possibly via the Chx10 gene.