Sections of undecalcified bone were stained with von Kossa and toluidine blue and images captured at original magnifications of ×2 (A), ×40 (B and C) to evaluate mineralized tissue (A, black), marrow adipocytes (B, white), and the mineralization fronts (C, yellow and green). The 12-month-old Sam68+/+ bone demonstrated a significant reduction in bone (A) and increase in marrow adipocytes (B) and a decrease in the distance between two consecutive fluorochrome labels (C). Magnification at source was ×40. Micrographs are representative of four to six screened in each group of animals.