highly significantP = 0.001
To investigate this pattern further, we applied a constrained analysis of principal coordinates on the data with strain as an explanatory variable with a correction for sex effects, which reveals a highly significant effect (ANOVA: P = 0.001, F 2,44 = 2.030) with R 2 = 0.0819 (R 2 adj = 0.0425) (Fig. 2B ).