Figure 5. Inner nuclear layer (INL) and outer nuclear layer (ONL) thickness and outer segment (OS) length in the central retina. A: INL thickness did not significantly differ among the genotypes at the any age examined. ONL thickness (B) and OS length (C) significantly differed among the genotypes at every age examined (* indicates p<0.05, Tukey–Kramer multiple-comparisons test). At 35 weeks of age, OS length in the homozygotes was too short to be measured by our method. We examined a single eye of three or four animals of each genotype at each age. Data shown are means±standard error.