Alizarin red stained [A] and micro-CT [B, C] images of long bones of 2 week [A], 3 week [B] or 5 week [C] old TH deficient Tshr−/− and Tshr+/− control mice. Arrowheads indicate epiphysis defects of the Tshr−/− tibia and femur as compared to the control bones from Tshr+/− mice. [D-G] Quantitative micro-CT data of the trabecular bone volume to total volume (Tb. BV/TV), trabecular number (Tb. N), trabecular thickness (Tb. Th), and trabecular spacing (Tb. Sp) of the tibia epiphyses of 3 week old vehicle or TH treated Tshr−/− mice and vehicle treated Tshr+/− control mice. Values are mean ± SEM (N = 5). The asterisk indicates a significant difference (P<0.01) in Tshr−/− mice treated with vehicle compared to TH treated Tshr−/− or vehicle treated Tshr+/− mice. Formation of the epiphysis both in the tibia and femur are severely compromised in TH deficient Tshr−/− mice and epiphyseal defects in Tshr−/− mice are completely rescued by 10 day treatment with TH.