Fig. 4.

Lack of syncytin-B does not impact on bone phenotype at 6 weeks of age.

RT-qPCR analysis of syncytin-A (A) and syncytin-B (B) transcript levels in WT and SynB^−/−male mice femurs at 6 weeks of age. Values were normalized to the geometric mean of 5 normalization factors (see Material and Methods). Syncytin-A expression displays no difference between the 2 genotypes, whereas as expected syncytin-B expression was only detected in WT mice. C. The amount of urinary deoxypyridinoline (DPD) crosslinks normalized by the amount of creatinine presented no difference between WT and SynB^−/− mice. D. Representative images of WT and Syn B^−/− femurs analyzed by μCT. E. Trabecular microarchitecture was assessed by μCT on femurs from 6 weeks old WT and SynB^−/− mice. No difference was observed when measuring the bone volume/tissue volume, or the trabecular thickness, number and separation. F. Representative pictures of TRAP positive OCs (arrows) on undecalcified femur sections from WT and SynB^−/− mice (Scale bar 50 μm). G. TRAP-positive multinucleated (2 nuclei and more) OCs were counted on undecalcified femur sections from WT and SynB^−/− mice and showed no difference. Black bars represent WT male mice, n = 9; white bars represent SynB^−/− male mice, n = 10. Results are shown as means ± S.E.M.