Immunohistochemistry analysis of Gas6 in the ovaries of porcine. a) Gas6 protein were staining brown by immunostaining using anti-Gas6 antibody (A, B, C and D), pre-immune serum instead of anti-Gas6 antibody was used as negative control (E). PRIFs, primary follicles; SECFs, secondary follicles; ANFs, antral follicles; MATFs, mature follicles. Scale bars=100 μm. b) The optical density of oocytes in different stage was analyzed by image-pro plus 6.0 software. The results are presented as mean ± SEM. GCs, granule cells.