Biology and Biotechnology of Follicle Development

Abstract

Growth and development of ovarian follicles require a series of coordinated events that induce morphological and functional changes within the follicle, leading to cell differentiation and oocyte development. The preantral early antral follicle transition is the stage of follicular development during which gonadotropin dependence is obtained and the progression into growing or atresia of the follicle is made. Follicular growth during this period is tightly regulated by oocyte-granulosatheca cell interactions. A cluster of early expressed genes is required for normal folliculogenesis. Granulosa cell factors stimulate the recruitment of theca cells from cortical stromal cells. Thecal factors promote granulosa cell proliferation and suppress granulosa cell apoptosis. Cell-cell and cell-extracellular matrix interactions influence the production of growth factors in the different follicular compartments (oocyte, granulosa, and theca cells). Several autocrine and paracrine factors are involved in follicular growth and differentiation; their activity is present even at the time of ovulation, decreasing the gap junction communication, and stimulating the theca cell proliferation. In addition, the identification of the factors that promote follicular growth from the preantral stage to the small antral stage may provide important information for the identification for assisted reproduction techniques.

The comprehensive mechanisms underlying nonhierarchical follicular development in geese (Anser cygnoides)

“…(Johnson and Woods, 2009;Palma et al, 2012). The results of the present study confirmed the complexity of this process, as 160 genes were identified, associated with various GO-terms, such as extracellular region, proteinaceous extracellular matrix, intermediate filament organization, peptidase activity, and endopeptidase activity.…”

Analysis of the Effect of Leukemia Inhibitory Factor on Follicular Growth in Cultured Murine Ovarian Tissue

“…Follicular growth involves several steps, including the primordial to primary follicle transition, recruitment of theca cells, formation of follicular antrum, and differentiation of cumulus cells [1,2]. Previous reports clarified that the mechanism through which follicular growth is regulated involves the interaction between oocytes and the surrounding granulosa, theca, and stromal cells in the ovary [1][2][3][4]. However, these studies were based on the culture of isolated follicles or on histological methods.…”

Number and density of equine preantral follicles in different ovarian histological section thicknesses

“…Histological evaluation has been used to determine the features of preantral follicle population, classification, stages of development, and morphology, as well as follicular density [12]. However, this methodology is time consuming and requires the development of technical approaches to overcome this problem [13].…”