EXPRESSION OF PAX-6 MESSENGER-RNA IN THE RETINAL DEGENERATION (RD) MOUSE

The homeobox gene Pax-6 is expressed during eye development in both th e retina and lens, and Pax-6 mutations cause ocular abnormalities incl uding retinal defects. We investigated the pattern of Pax-6 gene expre ssion in the rd/rd mouse model of inherited retinal degeneration in co mparison with nondegenerative controls, using Northern blot, reverse-t ranscription (RT)-PCR and in situ hybridization analysis. We observed an increased level of Pax-6 mRNA expression in the degenerative state, which appeared to affect equally the major Pax-6 exon 5a transcriptio nal splice variants as detected by RT-PCR. By in situ hybridization, P ax-6 mRNA was localized to the inner nuclear and ganglion cell layers of nondegenerative retina, but showed a more diffuse signal pattern in the rd/rd retina. This modulation of Pax-6 mRNA levels and localizati on is suggestive of activation of expression in retinal glial cells an d may reflect reorganization of cellular interactions in response to t he degenerative processes. (C) 1998 Academic Press.