J:83546

86 markers at an average resolution of 15.7 cM were screened in 268 (BALB/cByJ x C57BL/6J-Tyr^c-2J)F2 animals to identify QTLs associated with age-related retinal degeneration. Parental strain BALB/cByJ exhibits greater retinal photoreceptor loss at 8 months of age compared to parental strain C57BL/6J-Tyr^c-2J.

A significant locus for age-related retinal degeneration, Arrd1, mapped to an interval spanning 32.5 cM - 37.5 cM on mouse Chromosome 6 with a peak LOD score of 13.5 between D6Mit209 and D6Mit284. C57BL/6J-derived alleles confer dominant resistance to retinal degeneration at Arrd1.

Arrd2 mapped to an interval spanning 11 cM - 21 cM on mouse Chromosome 10 with a peak LOD score of 6.4 between D10Mit213 and D10Mit126. C57BL/6J-derived alleles confer additively inherited resistance to retinal degeneration at Arrd2.

Arrd3 mapped to a broad interval spanning 23.4 cM - 55.2 cM on mouse Chromosome 16 with a peak LOD score of 7.1 between D16Mit60 and D16Mit139. BALB/cByJ-derived alleles confer dominant resistance to retinal degeneration at Arrd3.

Suggestive QTLs mapped to 5 cM on mouse Chromosome 14 with LOD=2.7 at D14Mit126, 38 cM on mouse Chromosome 18 with LOD=2.6 at D18Mit208, 16 cM on mouse Chromosome 12 with LOD=2.6 at D12Mit60, 24 cM on mouse Chromosome 13 with LOD=2.5 at D13Mit19, and 53 cM on mouse Chromosome 8 with LOD=2.1 at D8Mit47. C57BL/6J-derived alleles confer resistance to retinal degeneration at all loci except D12Mit60 where BALB/cByJ-derived alleles confer resistance.