Abstract
This study determined the immunolocalization of transforming growth factor-β1 (TGF-β1) in the ovarian follicles of the adult mouse at diestrus, proestrus and estrus (10 and 12.5 h after treatment with hCG). The majority (≥72%) of the oocytes were stained positive in type 3b through to type 8 follicles. TGF-β1 staining in the granulosa and theca cells was first observed in type 5b follicles. The percentage of follicles with positively stained granulosa cells increased with follicular development from type 6 to 8 (13 to 82%). The percentage of follicles with positively stained theca cells did not show a clear trend (~30%) up to 10 h after hCG treatment, but increased in type 7 (79%) and unovulated type 8 (55%) follicles during the ovulation period (12.5 h after hCG). These results indicate that TGF-β1 is involved in follicular development and differentiation.
