RETINAL DEGENERATION SLOW (RDS) IN MOUSE RESULTS FROM SIMPLE INSERTION OF A T-HAPLOTYPE-SPECIFIC ELEMENT INTO PROTEIN-CODING EXON-II

Retinal degeneration slow (rds) is a semidominant mutation of mice tha t causes dysplasia and degeneration of rod and cone photoreceptors. Mu tations in RDS, the human ortholog of the rds gene, are responsible fo r several inherited retinal dystrophies including a subset of retiniti s pigmentosa. The normal rds locus encodes rds/peripherin, an integral membrane glycoprotein present in outer segment discs, Genomic librari es from wildtype and rds/rds mice were screened with an rds cDNA, and phage lambda clones that span the normal and mutant loci were mapped. We show that in mice, rds is caused by the insertion into exon II of a 9.2-kb repetitive genomic element that is very similar to the t haplo type-specific element in the H-2 complex. The entire element is includ ed in the RNA products of the mutant locus. We present evidence that r ds in mice represents a null allele. (C) 1995 Academic Press, Inc.