highly significantp < 0.001
Comparison of the proportion of mice in estrus among females with AR < 6 kOm and AR > 6 kOm ( Figure 5 ) showed highly significant differences in all strains studied: CD-1 (χ 2 = 85.924, df = 1, p < 0.001), FVB/N (χ 2 = 53.539, df = 1, p < 0.001), and C57Bl6/J (χ 2 = 64.744, df = 1, p < 0.001).