FITC-labeled Peanut Agglutinin (PNA) staining revealed that cone photoreceptors were abundant in the central and peripheral regions of the untreated, P14 rd12 mouse retina (c, d), a pattern similar to that seen in the P14, wild type mouse retina (a, b). Cones degenerate in the rd12 retina by 5 weeks of age (e), remaining only in the dorsal and temporal regions through at least 5 months (f). Arrows: fragments of RPE cells. D: dorsal; V: ventral; T: temporal; N: nasal.