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

We examined the role of retinoid-related orphan receptor (ROR)beta, a membe r of the nuclear receptor family of transcription factors, in retinal neuro genesis. In situ hybridization studies showed that ROR beta is expressed in retinal progenitor cells in the embryonic rat retina. Further studies demo nstrated that ROR beta colocalizes with Chx10, a transcription factor thoug ht to influence retinal progenitor proliferation (Burmeister, M., Novak, J. , Liang, M-Y., Basu, S., Ploder, L., Hawes, N.L. Vidgen, D., Hoover, F., Go ldman, D., Kalnins, V.L, Roderick, T.H., Taylor, B.A., Hankin, M.H. and McI nnes, R.R., 1996. Ocular retardation mouse caused by Chx10 homeobox null al lele: impaired retinal progenitor proliferation and bipolar cell differenti ation. Nat. Genet. 12, 376-383). Northern analysis reveals that ROR beta ex pression is dramatically decreased in the ocular retardation(J) mutant, whi ch possesses a defect in the Chx10 gene. Overexpression of ROR beta in reti nal progenitors by biolistic transfection results in an increase in the num ber of large cell clones. These data support a role for ROR beta in regulat ing retinal progenitor proliferation, possibly via the Chx10 gene. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.