PARENT SESSION
Follicular Development
105
IMMUNOHISTOCHEMICAL LOCALIZATION OF ACTIVIN-A AND FOLLISTATIN IN GOAT FOLLICLES.
Shidaifat, Falah1, Shoter, Ali1, Al-Katib, Ahed1, 1
ABSTRACT- Activin-A and its binding protein, follistatin, are antagonistic regulators of mammalian reproduction. Their protein localization by goat follicular cells in association with follicular size was investigated by immunohistochemical analysis. The results revealed a stage-dependent localization of activin-A and follistatin to the granulosa cells, being more abundant in non-atretic than atretic follicles. Activin-A immunoreactive signals were localized uniformly to the granulosa cells of healthy preantral and antral follicles. However, the protein localization pattern appeared to be more intense in large antral follicles as compared to preantral and small antral follicles. Although, activin-A was detected in the granulosa cells of atretic follicles, its immunoreactive signals appeared to be scattered and weak. Like activin-A, its binding protein was also localized to the granulosa cells of goat follicles. Although, weak immunoreactive signals were detected in the preantral and small antral follicles, intense and strong signals were detected in the granulosa cells of large antral follicles. The distributions of follistatin signals were limited to inner layer of the granulosa cells. The atretic follicles displayed weak and decreased expression of follistatin protein. The localization pattern of activin-A and its binding protein in healthy and atretic follicles suggested the existence of a balanced antagonistic control system that is required to coordinate goat follicular growth and atresia.
KEY WORDS: goat, follicle, activin, follistatin