FSH induction of granulosa cell differentiation

Ovarian follicles, the basic unit of the ovary, consist of an outer layer of theca interna cells which encircle inner layers of granulosa cells. Granulosa cells, in turn, surround the innermost oocyte-cumulus complex. This complex array of cell layers is essential for the maturation and ovulation of the ovum. Significantly, the granulosa cell, by virtue of its close interaction with the outer theca and inner oocyte-cumulus compartment, serves to integrate information necessary for the achievement of successful follicular development. 

Although the granulosa cell is subject to different varieties of signaling systems, FSH is the most important hormone for its differentiation. Specifically, FSH stimulates the granulosa cells to secrete estrogens and progestins, as well as various nonsteroidal substances [43]. The induction of various hormone receptors in the granulosa cell is also FSH dependent. 

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