Fig. 4
Epistasis influenced adult Pax6 mRNA levels. Pax6 mRNA transcripts from (a–c) embryonic day 18.5 (E18.5) brains, (d–f) adult retinas, and (g–i) adult corneas of Pax6+/+ (Wt), Pax6Sey/+ (Het), Pax6Sey/Sey (Hom; E18.5 brains only), were measured on three genetic backgrounds (bkgds): C57BL/6J (B6), B6129F1 (F1), and 129S1/SvImJ (129). Three RT-ddPCR assays were used to measure Wt (Wt-specific), Sey (Sey-specific), and both Wt and Sey combined (non-specific) Pax6 transcript levels. Pax6-genotype was found to influence Wt-, Sey-, and Non-specific Pax6 transcript levels in all tissues. Similarly, bkgd influenced at least one Pax6 transcript levels in all tissues. Epistasis between Pax6 genotype and bkgd was also measured in retinal mRNA samples, and indicated on the graphs (red). For Wt-specific Pax6 transcripts, post hoc analysis revealed that retinas from Wt B6 mice had lower transcript levels than retinas from Wt F1 and Wt 129 mice (**p < 0.005 and ***p < 0.001; respectively) and retinas from Het B6 mice had significantly lower Wt-specific Pax6 transcript levels than retinas from Het 129 mice (p < 0.05). Post hoc analysis of Sey-specific Pax6 transcripts also revealed that retinas from Het B6 mice had lower Sey-specific Pax6 transcript levels than retinas from 129 mice (p < 0.005). Not significant (N.S.). Statistical significance was determined using ANOVA, post hoc analysis was performed using Fisher’s LSD with Bonferroni’s correction for multiple comparisons. Each dot represents an individual mouse and error bars represent the mean ± the standard deviation
