GENETICALLY-ENGINEERED LARGE ANIMAL-MODEL FOR STUDYING CONE PHOTORECEPTOR SURVIVAL AND DEGENERATION IN RETINITIS-PIGMENTOSA

Patients with retinitis pigmentosa (RP) typically develop night blindn ess early in life due to loss of rod photoreceptors. The remaining con e photoreceptors are the mainstay of their vision; however, over years or decades, these cones slowly degenerate, leading to blindness. We c reated transgenic pigs that express a mutated rhodopsin gene (Pro347Le u). Like RP patients with the same mutation, these pigs have early and severe rod loss; initially their cones are relatively spared, but the se surviving cones slowly degenerate. By age 20 months, there is only a single layer of morphologically abnormal cones and the cone electror etinogram is markedly reduced. Given the strong similarities in phenot ype to that of RP patients, these transgenic pigs will provide a large animal model for study of the protracted phase of cone degeneration f ound in RP and for preclinical treatment trials.