Survey of common eye diseases in laboratory mouse strains

As in human populations, in which founder mutations have been identified in groups of families, a number of founder mutations have been observed across strains in mice. In this report, we provide a phenotype and genotype survey of three common eye diseases in the collection of JAX mice strains at The Jackson Laboratory (JAX). These eye diseases are retinal degeneration 1 (Pde6b(rd1)), retinal degeneration 8 (Crb1(rd8)), and cone photoreceptor function loss 3 (Gnat2(cpfl3)).

Ocular lesions for rd1 and rd8 were evaluated by fundus examination and fundus photography, and the abnormal retinal function observed in mice homozygous for cpfl3 was assessed by ERG. Genotyping protocols for rd1, rd8, and cpfl3 mutations were performed by PCR with appropriate primers.

We have actively screened retired breeders for surface dysmorphologies, and for intraocular defects by indirect ophthalmoscopy, slit-lamp biomicroscopy, and ERG to discover new spontaneous mutations in strains from the Genetic Resource Science (GRS) production colony. Through this process, we have found that of the strains screened, 99 strains carried the rd1 mutation, 85 strains carried the rd8 mutation, and 20 strains carried the cpfl3 mutation.

Of the 1000 of strains screened during this study, 204 carried one of three founder mutations in Pde6b, Crb1, or Gnat2. Since these three retinal mutations occur commonly in various mouse strains, genotyping for these mutations, and/or avoiding mouse strains or stocks carrying these mutant alleles when studying new retinal disorders is recommended. The robust PCR genotyping protocols to test for these common alleles are described herein.