Abstract
Abstract: :
Purpose: Progressive rod cone degeneration (prcd) is an autosomal recessive retinal degeneration, one of many forms of Progressive Retinal Atrophy (PRA) affecting dogs. As prcd has been mapped to CFA9, syntenic conservation suggests it as an animal model of RP17. To expand the number of informative pedigrees available for fine scale linkage mapping of the prcd region and expedite positional cloning of the disease gene, we have tested other dog breeds with retinal degeneration for allelism with prcd. Method: Laboratory strains of prcd-affected dogs, derived either from Miniature Poodles or English Cocker Spaniels, were test mated to PRA-affected dogs from 5 other breeds [Australian Cattle Dog (ACD), Basenji, Italian Greyhound, Nova Scotia Duck Tolling Retriever (NSDTR), Portuguese Water Dog (PWD)]. Disease status of the offspring was evaluated by histological examination of retinas at 12 to 16 weeks of age. SNPs along CFA9 were used to fine map the prcd region and define breed specific SNP haplotypes. Results: All retinas from progeny of ACD, NSDTR or PWD test breedings had morphologic abnormalities diagnostic of prcd. Retinas from test bred progeny of Basenji and Italian Greyhound were normal. prcd affected ACDs and NSDTRs shared a different CFA9 haplotype from that common to prcd affected PWDs and all other previously recognized prcd affected pedigrees. Conclusions: PRA in ACD, NSDTR and PWD is prcd, but this is not the case for disease in Basenji or Italian Greyhound. This increase in prcd -informative pedigrees will accelerate fine scale mapping of the disease locus. Support: EY06855, EY13132, Foundation Fighting Blindness, Morris Animal Fdn./The Seeing Eye Inc., Van Sloun Fund for Canine Genetic Research, Australian Cattle Dog Club of America, Basenji Club of America, Italian Greyhound Club of America, Portuguese Water Dog Club of America. Disclosure Codes: I, C, P.
Keywords: 316 animal model • 562 retinal degenerations: hereditary • 457 linkage analysis