(A) Adult WT XLacZ+/− mosaic eye showing characteristic radial stripes in the corneal epithelium. (B) Adult Pax6+/− XLacZ+/− mosaic eye showing disrupted patterns with larger, more irregular patches. (C) Section through cornea of a 3-week old XLacZ+/− mosaic mouse eye showing β-gal positive and β-gal negative patches that were measured in the basal corneal epithelium. (D, E) Corrected stripe numbers per circumference (D) and corrected stripe numbers per mm of corneal circumference (E) for corneal epithelia from adult WT and Pax6+/−, X-inactivation mosaics at 15 and 30 weeks. Statistical comparisons were made by 2-way analysis of variance (ANOVA) followed by pairwise Bonferroni post-hoc tests. (F, G) Corrected mean patch lengths (in cell numbers across the corneal diameter of the basal corneal epithelium) for the β-gal positive cell population (F) and median patch lengths for the minor cell population (G) in WT and Pax6+/− mosaics at 3 weeks. Statistical comparisons were made by Student’s t-test with Welch’s correction (F) and Mann-Whitney U-test (G). (H, I) Mean numbers of cells (H) and patches (I) across the corneal diameter of the basal corneal epithelium in WT and Pax6+/− mosaics at three ages. Statistical comparisons were made by 2-way ANOVA followed by pairwise Bonferroni post-hoc comparisons of genotypes and separate linear regression analyses of ages for WT and Pax6+/− genotypes. Abbreviations: WT, wild-type; NS, not significant; *P<0.05; **P<0.01; ***P<0.001; ****P<0.0001. In D and E, corrected stripe numbers were calculated for both eyes and the mean value for each mouse was used for analysis. In F-I, the central histological section of one eye per mouse was analysed. The numbers of eyes per group is shown within the bars. Error bars are 95% CI. Scale bars: A,B = 1 mm; C = 100 µm.