Dosage effect of TgSGP. (A) Comparison of 2-month-old Csf1^op/Csf1^op; TgSGP4/+ and Csf1^op/Csf1^op; TgSGP4/TgSGP4 femurs. Top panel: x-ray. Bottom panel: histology of the bone sections. Low-power photomicrographs of comparable fields of 5-μm sections of distal femoral metaphyses stained with H&E. Bar, 50 μm. (B) Histomorphometric analyses of femurs from 2-month-old mice (average from femurs from 2 mice). Dose-dependent correction of skeletal parameters in mice expressing TgSGP but not TgSPP. Also note correction by TgCS. BV/TV indicates bone volume/total volume; Tb.Sp, trabecular spacing; and Tb.N, trabecular number.