DMP1-Cre–mediated loss of Gsα in osteocytes. (A) Breeding strategy for generating mice with osteocyte-specific disruption of Gsα. (B) Top panel: Schematic representation (not to scale) showing the relative location of loxP sites (triangles), Gsα-exon 1 (rectangle), multiplex PCR primers (F1, R1, R2), and the expected PCR product sizes. Bottom panel: PCR analysis showed Gsα allele recombination in skeletal (tibia and calvaria) tissue but not in hematopoietic (BM, spleen, and liver) tissues from OCY-GsαKO mice (n = 3). (C) Relative expression of Gsα in femur and tibia (n = 4) from control (Con) and OCY-GsαKO (KO) mice. Gsα mRNA expression in (D) osteoblasts, BM, spleen, (E) Gr1⁺ flow-sorted granulocytes, and (F) F4/80⁺ CD11b⁺ flow-sorted monocytes/macrophages (n = 4). (G) cAMP synthesis in calvarial osteoblasts isolated from control and OCY-GsαKO mice in response to PTH and forskolin (FSK; n = 4). (H) von Kossa staining of femurs showing osteopenia in OCY-GsαKO (KO) mice compared with control (Con) mice. (I-J) Whole-body dual-emission x-ray absorptiometry showing (I) bone mineral density (BMD; g/cm²) and (J) bone mineral content (BMC; g) in young (7 weeks old) and adult (21 weeks old) mice (n ≥ 7 mice). Error bars represent mean ± SEM. *P < .05 by t test.