Figure 3. Linkage and sequence data

A: Ninety-two back-cross progeny from the (B6-rd12 X CAST/EiJ)F1 X B6-rd12/rd12 were phenotyped for ERG phenotype and genotyped for the indicated microsatellite markers. The black boxes represent homozygosity for B6 derived allele and white boxes represent heterozygosity, B6 and CAST derived alleles. The number of chromosomes sharing the corresponding haplotype is indicated below each column of squares. The order of marker loci was determined by minimizing the number of crossovers. The genotype for rd12 was inferred from the phenotype. rd12 and D3Mit19 are tightly linked with no crossover (0/92). B: Genetic map of Chromosome 3 in the rd12 region showing the closest markers (D3Mit19 at position 87.60 cM), the retinal expressed gene Rpe65 and the region of human homology (1p31). C: The nucleotide sequences around the single base substitution at position 130 (C to T) in exon 3 are shown for the wild type (WT) allele and the rd12 allele of the Rpe65 gene (GenBank accession number: AF410461). A novel mutation changes codon 44 CGA to a stop codon TGA (amino acid change: Arg44Ter) in the Rpe65 gene in rd12 mice.