Figure 1.

ENU mutagenesis and skeletal screening strategy. (A) ENU-mutagenized G0 male mice are outcrossed with C57BL/6J females to generate male G1 mice, which are then outcrossed with C57BL/6J females. Resulting G2 female mice are back-crossed to their G1 sire, and all resulting G3 mice undergo DXA and X-ray imaging. Automated meiotic mapping identifies ENU-induced alleles segregating with phenotypic variation, and statistical significance is visualized by Manhattan plot. Alleles exceeding Bonferroni multiple-test correction (red line) are considered associated with phenovariance. (B-F) Left: Prior to statistical modeling, all phenotypes were significantly correlated with age and gender in both male (blue) and female (pink) mice. Numbers of mice used for modeling and percent of variation explained by age and gender are shown in Supplementary Table 2. Right: Residual differences between predicted and actual values among N~25,300 mice confirm statistical modeling (see Methods) successfully removes variation due to age and gender. Dashed horizontal line indicates no variation. Solid colored lines are smoothing lines (estimated by lowess) indicating the trends in residual measures against age. Individual male mice are shown in blue and female mice shown in pink, with male and female trend lines shown in blue and red, respectively.