Osteocyte size and circularity. Quantification of the relative size and circularity of (A, B) lacunae containing viable osteocytes and (C, D) empty lacunae in cortical bone from wild-type (WT) and Cx43 conditional knockout (cKO) mice following three weeks of normal loading conditions (Control) or mechanical unloading via hindlimb suspension (Suspended). Lacunae were quantified within a 2400 μm linear region of the mid-diaphysis of the femur. Mean ± SE. * indicates a significant difference (p < 0.05) between Control and Suspended within a genotype, while † indicates a significant difference (p < 0.05) between WT and cKO within a loading condition. n = 5/group.