Cx43 expressing osteocytes. Left: Representative images demonstrate the relative absence of Cx43+ osteocytes in the femur midshaft cortical bone of cKO mice compared to WT. Red arrow: Cx43+ osteocyte, blue arrow: Cx43- osteocyte, white arrow: empty lacunae. The black bar represents 25 μm. Right: Cross-sections of the femur midshaft taken via light microscope reveal the osteopenic cortical phenotype of cKO mice. The black bar represents 1000 μm.