Analysis of genes differentially expressed during retinal degeneration in three mouse models.

An estimated 100,000 people in the US alone have retinitis pigmentosa. This disease, caused by the loss of rods and cones, results in blindness. With the intention of identifying common cell death pathways that result in RP, the pattern of global gene expression in three different mouse models of retinal degeneration was analyzed using DNA arrays. The models used were opsin ( Delta255-256 ), a transgenic mouse line that expresses a mutant form of opsin with a deletion of an isoleucine at either position 255 or 256; the Bouse C mouse, whereby normal opsin is over-expressed by over 2 folds; MOT1, a model that expresses SV-40 T antigen downstream of opsin promoter and leads to retinal degeneration. We found that, at least in the 2 models of retinal degeneration that are characterized by rhodopsin abnormalities, death is due to the TNF pathway. In addition, there are a number of unknown genes not yet annotated in each of the models that could be promising in revealing novel functions in photoreceptors.