RETINAL DEGENERATION IN THE RD MOUSE IS CAUSED BY A DEFECT IN THE BETA-SUBUNIT OF ROD CGMP-PHOSPHODIESTERASE

MICE homozygous for the rd mutation display hereditary retinal degeneration and the classic rd lines serve as a model for human retinitis pigmentosa1,2. In affected animals the retinal rod photo-receptor cells begin degenerating at about postnatal day 8, and by four weeks no photoreceptors are left3. Degeneration is preceded by accumulation of cyclic GMP in the retina4 and is correlated with deficient activity of the rod photoreceptor cGMP-phospho-diesterase5. We have recently isolated a candidate complementary DNA for the rd gene6 from a mouse retinal library and completed the characterization of cDNAs encoding all subunits of bovine photoreceptor phosphodiesterase7. The candidate cDNA shows strong homo logy with a cDNA encoding the bovine phospho-diesterase β subunit. Here we present evidence that the candidate cDNA is the murine homologue of bovine phosphodiesterase β cDNA. We conclude that the mouse rd locus encodes the rod photoreceptor cGMP-phosphodiesterase β subunit. © 1990 Nature Publishing Group.