Analysis and quantitation of mRNAs encoding the alpha- and beta-subunits of rod photoreceptor cGMP phosphodiesterase in neonatal retinal degeneration(rd) mouse retinas

The retinal degeneration (rd) mouse is a commonly-studied animal model of t he family of human-inherited retinal blindness known as retinitis pigmentos a, and is a likely model in which therapies For these conditions will conti nue to he developed and tested, Mutation of the beta-subunit of the rod pho toreceptor cell-specific cyclic CMP phosphodiesterase is known to cause pho toreceptor apoptosis in these mice. However, the molecular phenotype of thi s mutation in terms of quantitative levels of the phosphodiesterase alpha- and beta-subunit messenger RNAs remains unknown. In this study, the express ion of the alpha- and beta-phosphodiesterase subunits is compared in C57BL/ 6J +/+, rd/+, and rd/rd mouse retinas. Using the techniques of quantitative reverse transcription polymerase chain reaction and quantitative in situ h ybridization, the expression of the subunit mRNAs was measured in retinas o f postnatal mice 0-14 days of age. Additionally, Full length coding sequenc es were amplified for both subunits, and the beta-phosphodiesterase subunit mRNA was further evaluated for evidence of alternative splicing. Lastly, a relative decrease in expression of the mutant beta-phosphodiesterase allel e in rd/+ mice was observed. (C) 2000 Academic Press.