Objective:To study the effect of follicle-stimulating hormone β（FSHβ） on bone morphogenetic protein 9（BMP9）-induced osteogenic differentiation in mouse embryonic fibroblasts（MEFs）. Methods:Ad Easy system was used for generating target recombinant adenoviruses（Ad-GFP

Ad-FSHβ

and Ad-BMP9）

and our investigation was designed into four groups:Ad-GFP group

Ad-BMP9 group

Ad-FSHβ group

and Ad-BMP9+Ad-FSHβ group. Chemiluminescence technique and histochemical staining were conducted to assay alkaline phosphatase（ALP）activity on day 3

5

and 7

Western blot to test the protein expression of Runx2 and Dlx5

RT-PCR to measure the m RNA expression of osteocalcin（OCN）and osteopontin（OPN）

and Alizarin Red S staining to detect the matrix mineralization. In addition

Flow cytometry was utilized for analysing the cell cycle of different groups. Results:Exogenous expression of FSHβ dramatically enhanced the ALP activity on day 3（6 874.67±224.93 vs. 11 935.67±568.76

P=0.000）

day 5（43 434.67±2 047.57 vs. 98 913.33±4 606.26

P=0.000）

and day 7（38 198.00±2 376.43 vs. 78 534.67±2 114.56

P=0.000）

and the protein expression of Runx2（1.171±0.105 vs. 1.350±0.053

P=0.026）and DLX-5（1.382±0.123 vs. 1.738±0.286

P=0.001）

and the m RNA expression of late osteogenic makers

namely OCN（1.300±0.045 vs. 1.471±0.046

P=0.002）and OPN（1.300±0.084 vs. 1.479±0.038

P=0.016）

and matrix mineralization induced by BMP9 in MEFs. Moreover

efficient infection of AdFSHβ or/and Ad-BMP9 remains no apparent influence on cell cycle in MEFs（G1-phase:F =0.226

P =0.876;G2-phase:F =0.147

P=0.929;S-phase:F=0.027

P=0.994）. Conclusion:FSHβ promotes BMP9-induced osteogenic differentiation without substantial effect on cell cycle in MEFs.