Developmental and tissue-specific expression of the rod photoreceptor cGMP-gated ion channel gene

Probes against the retinal cGMP-gated cation channel were generated by PCR amplification of cDNA from rat and bovine retina. Southern and Northern analyses showed that the channel is encoded by a single gene that gives rise to a single mRNA species of 3.2 kb. Low levels of cGMP-gated channel RNA were detected in postnatal day 1 (PN 1) retinas and the amount increased to adult levels over the next two weeks of development. Screening of a number of tissues by Northern blot hybridization and by PCR amplification showed the channel to be expressed by heart and kidney as well as retina, but not by cerebellum, cerebral cortex, liver, muscle, olfactory bulb, spleen, testes or thymus.