Review: Roles of follicle-stimulating hormone in preantral folliculogenesis of domestic animals: what can we learn from model species and where do we go from here?

The pituitary gonadotropin FSH is a glycoprotein critical for the development of ovarian follicles. Upon binding to its G protein-coupled membrane receptor located on the granulosa cells of ovarian follicles, FSH elicits a cascade of downstream intracellular responses to promote follicle growth, maturation and steroidogenic activity, leading to the acquisition of meiotic and developmental competence of the enclosed oocyte. The essential role of FSH for proper antral follicle development and fertility is indisputable; over the decades, increasing evidence has also pointed toward survival and growth-promoting effects elicited by FSH in earlier-stage preantral follicles, deeming these follicles FSH-responsive as opposed to the FSH-dependent antral follicles.

Isolation of Small Preantral Follicles from the Bovine Ovary Using a Combination of Fragmentation, Homogenization, and Serial Filtration.

Understanding the full process of mammalian folliculogenesis is crucial for improving assisted reproductive technologies in livestock, humans, and endangered species. Research has been mostly limited to antral and large preantral follicles due to difficulty in the isolation of smaller preantral follicles, especially in large mammals such as bovine species. This work presents an efficient approach to retrieve large numbers of small preantral follicles from a single bovine ovary.