Cell proliferation and differentiation were reduced in female Col3.6-HSD2 (TG) osteoblast cultures. A) Alkaline phosphatase (red) and von Kossa (black) staining of primary calvarial osteoblast cultures from 6- to 8-day old WT and TG mice. B) Alkaline phosphatase activity at days 7, 14 and 21 from WT and TG neonatal osteoblast cultures. C) Expression of mRNA of Col1a1, bone sialoprotein (BSP), and osteocalcin (OCN) in WT and TG primary neonatal osteoblast cultures at days 7, 14 and 21. D) Cell growth in osteoblast cultures from neonatal WT and TG mice. E) Incorporation of BrdU in primary osteoblast cultures from neonatal WT and TG mice. F) Serum osteocalcin (OCN) level in females measured by ELISA. Each value is the mean ± SD for 3 (A–C) or 6 (D–F) samples per group and each experiment has been performed at least twice with similar results. Black bars, WT; White bars, TG. *Different than WT, *p<0.05, **p<0.01.