Abstract
Abstract: :
Purpose: To establish transgenic mice lines expressing Cre-recombinase in retinal photoreceptors or retinal pigment epithelium (RPE) for generating cell-type specific (conditional) mutants. Methods: 5’ upstream sequences of the following genes were cloned by LA-PCR into cre-expression plasmids: red and green pigment gene for targeting to M-cones, blue pigment gene for S-cones, cGMP phosphodiesterase ß-subunit (ßPDE) gene for rods; and RPE65 for targeting to RPE. Transgenic mice were generated, analyzed histologically, and lines established. The lines were also crossed with ROSA26 mice, which contain a conditional lacZ reporter cassette that can be activated by cre-recombinase. Results: Immunofluorescence study of Cre recombinase shows successful targeting to RPE or cone cells in the respective transgenic lines. Mating with ROSA26-lacZ mice (containing floxed ß- galactosidase gene) revealed functional cre-recombinase expression. Further analysis of various transgenic lines is in progress. Conclusions: We have established Cre-expressing transgenic mice lines for targeting to RPE and M-cones. Cre-lines for S-cone and rod targeting are being evaluated. Since mutations in several widely-expressed genes (e.g., RPGR) lead to retinal degeneration, these transgenic mice should be valuable in generating conditional knockouts to investigate their role specifically in photoreceptors and RPE.
Keywords: animal model • transgenics/knock-outs • retinal degenerations: hereditary