(A) Bone mineral density (BMD) measured in whole body, femur, tibia, and lumbar spine (L4–L6) in 5-month-old β-thalassemia mice (Hbbth3/+ mice) and compound Hbbth3/+;Erfe-/- mutants. (B) Representative section of femoral epiphyses stained with Von Kossa, and quantitative estimates of bone volume (BV/TV) and trabecular thickness (Tb.Th). (C) Dynamic histomorphometry following two i.p. injections of calcein (green) and xylenol orange (red) given at days 8 and 2, respectively. Shown are measured and derived parameters, namely mineralizing surface (MS), mineral apposition rate (MAR) and bone formation rate (BFR). (D) Representative image of TRAP (ACP5) staining of femoral epiphysis, also showing both osteoclast surface (Oc.S) and number (N.Oc), expressed as a function of bone surface (BS). Statistics: Mean ± SEM; unpaired two-tailed Student’s t-test; *p<0.05, **p<0.01; N = 4–5 mice per group.