Analysis and Quantitation of mRNAs Encoding the α- and β-Subunits of Rod Photoreceptor cGMP Phosphodiesterase in Neonatal Retinal Degeneration (rd) Mouse Retinas

Abstract

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 β-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 α- and β-subunit messenger RNAs remains unknown. In this study, the expression of the α- and β-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 β-phosphodiesterase subunit mRNA was further evaluated for evidence of alternative splicing. Lastly, a relative decrease in expression of the mutant β-phosphodiesterase allele in rd /+ mice was observed.