Supplemental Figure 1Male MRTFA KO mice exhibited mild osteopenic phenotype. WT (n = 7) and MRTFA KO (n = 7) male mice (17 weeks old) were euthanized and then weighed. The femurs and tibiae of the mice were then dissected, and the bone lengths were measured with a caliper. Whole body weights (A), femur lengths (B), and tibia lengths (C) of WT and KO mice Transverse images scanned by the micro-CT were traced manually with a computer program and stacked to render 3D images. Representative three-dimensional images of cortical region (mid-shaft of femurs) and trabecular region of femurs generated by μCT analysis (D). The cortical total volume (E), cortical bone volume (F), cortical thickness (G), cortical bone volume/total volume ratio (BV/TV) (H), and trabecular bone volume fraction (BV/TV) (I). Data are expressed as mean ± SEM (n = 3). *p < 0.05; **p < 0.01.