Abstract
Purpose: :
Progressive retinal atrophy (PRA) is a heterogeneous group of heritable retinopathies causing blindness in cats and dogs. A complete and early–onset retinal degeneration with autosomal recessive inheritance has been described in the Persian breed of cats. Our objective was to genetically map the PRA–causing locus in cats to identify causative genes.
Methods: :
The feline PRA pedigree includes 66 individuals for linkage mapping and disease characterization. Ophthalmic and neuro–ophthalmic examinations were performed on each animal on multiple occasions to determine disease status and aid identification of similar diseases in other species. Genomic DNA was extracted either from blood samples or splenic tissue. Genome–wide scan was performed for 66 cats representing a 5 generational Persian PRA pedigree. Feline–specific microsatellite markers were selected from feline linkage/RH maps with an average spacing of 10cM. Two–point linkage analysis was performed using the program LINKAGE. For fine mapping, additional markers flanking the critical regions were analyzed.
Results: :
Genome–wide scan suggested a critical region on B1p flanked by FCA014 and FCA806. A maximum LOD score value of 2.06 at 17cM and 2.14 at 11.8cM was obtained for each marker, respectively. Poor coverage of the feline map prevents adequate comparison between humans, cats and dogs in this region and does not clearly suggest a candidate gene.
Conclusions: :
A novel genetic locus on B1p has been identified for this feline rod–cone dysplasia in Persian breed of cats.
Keywords: retinal degenerations: hereditary • linkage analysis • genetics