DYSTROPHINS IN DEVELOPING RETINA - DP260 EXPRESSION CORRELATES WITH SYNAPTIC MATURATION

DYSTROPHIN, the protein altered in Duchenne muscular dystrophy (DMD), is necessary for normal retinal function and exists in several isoform s. We examined the expression of dystrophin and utrophin proteins and transcripts in the rat retina at different developmental stages using Western blots and semi-quantitative RT-PCR. Our results revealed the p resence of utrophin (DRP1), G-utrophin and/or DRP2 and four dystrophin isoforms (Dp427, Dp260, Dp140, Dp71) in the normal adult rat retina. Only Dp260 showed a marked progressive increase with age at both prote in and mRNA levels. This variation is consistent with the establishmen t of synaptic functions in the developing retina and suggests a key ro le for this apo-dystrophin in synaptogenesis.