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 the family of human-inherited retinal blindness known as retinitis pigmentosa, and is a likely model in which therapies for these conditions will continue to be developed and tested. Mutation of the beta-subunit of the rod photoreceptor cell-specific cyclic GMP phosphodiesterase is known to cause photoreceptor apoptosis in these mice. However, the molecular phenotype of this mutation in terms of quantitative levels of the phosphodiesterase alpha- and beta-subunit messenger RNAs remains unknown. In this study, the expression 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 hybridization, the expression of the subunit mRNAs was measured in retinas of postnatal mice 0-14 days of age. Additionally, full length coding sequences 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 allele in rd /+ mice was observed. Copyright 2000 Academic Press.