The Retinal homeobox gene, Rx, is expressed in the anterior neural plate and the optic vesicle shows Rx expression throughout development. Rx is required for the proliferation of retinal progenitor cells during eye development.;Our expression studies of the Rx gene in the adult mouse retina show Rx expression in the Photoreceptor and inner nuclear layer of the adult neural retina and ciliarybody. The cotransfection assays indicate that Rx supports the transcription of neural retinal markers, as well as the RPE-markers. Therefore we characterize Rx as a proliferation marker for the entire optic vesicle region.;To determine the mechanism of Rx-mediated regulation of its target genes, we studied the BMP-4 promoter sequence. The mutation in one PCE-1 site significantly reduced the activity of BMP-4 promoter. Also the construct with all three PCE-1 mutated sites, show decreased activity. The 3\u27 end of the promoter by itself also shows reduced promoter activity
