Retinal degeneration and RPE transplantation in Rpe65(-/-) mice.

Purpose: To determine whether transplanting normal retinal pigment epithelium (RPE) into the subretinal space influences photoreceptor function and degeneration in Rpe65(-/-) mice.

Methods: RPE cells were isolated from eyes of normal mice and transplanted to the subretinal space of one eye of Rpe65(-/-) mice. The other eye received a subretinal injection of saline or was not touched.

The positive role of the carboxyl terminus of the gamma subunit of retinal cGMP-phosphodiesterase in maintaining phosphodiesterase activity in vivo.

The inhibitory rod cyclic GMP-phosphodiesterase gamma subunit, PDEgamma, is a key component of the photoresponse and is required to support rod integrity. Pdeg(tm1)/Pdeg(tm1) mice that lack PDEgamma due to a targeted disruption of the gene encoding PDEgamma, (Pdeg) suffer from a very rapid and severe photoreceptor degeneration. Previously, deletions in the carboxyl-terminal domain of PDEgamma blocked its ability to inhibit trypsin-activated PDE activity, in vitro.