Ovary is an important organ that houses the oocytes (reproductive cell). Oocyte growth depends on the function of follicular cells such as the granulosa and theca cells. Two-cell two gonadotropin systems are associated with oocyte growth and follicular cell functions. In addition to these systems, it is also known that several growth factors regulate oocyte growth and follicular cell functions....

This review chronicles the key concepts, studies, advancements and terms that have led to our current understanding of turnover of dominant follicles (growth and atresia) during the bovine estrous cycle. The "two-wave" concept of follicular development was first proposed in 1960, but remained controversial for the next 28 yr. The concept of the "dominant" follicle was adapted to cattle in 1987....

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 fo...

A rapid return to estrus after weaning maximizes productivity in sow herds. Return to estrus is influenced by season and production factors (eg, parity and body condition).1-4 The effects of season and production factors on postweaning interval to estrus are mediated by ovarian follicular development.5,6 Sows with small follicles (< 4 mm) at day 3 after weaning were more likely to experience an...

Foxo transcription factors have been implicated in diverse biological processes, including metabolism, cellular stress responses, and aging. Here, we show that Foxo3a-/- female mice exhibit a distinctive ovarian phenotype of global follicular activation leading to oocyte death, early depletion of functional ovarian follicles, and secondary infertility. Foxo3a thus functions at the earliest stag...

Growth factors of endocrine and/or paracrine origin play determinant roles in antral follicular development. They modulate survival, proliferation and differentiation of follicular cells, acting in interaction with gonadotropins. It is thought that factors belonging to the families of the insulin-like growth factor (IGF-I and -II), epidennal growth factor (EGF and TGF-a) and fibroblast growth f...

Intra-ovarian regulation of follicular maturation is modulated by various factors. Among these, growth factors are important local actors. We examined the immunohistochemical localization of transforming growth factor alpha (TGF-alpha), epidermal growth factor (EGF) and epidermal growth factor receptor (EGF-R) in 18 human ovaries. The concentration of TGF-alpha and EGF in follicular fluid was m...

Follicular development is controlled partly by intra-ovarian and intrafollicular factors within the ovary and partly by extra-ovarian events. Many oocyte derived factors and granulose cell factors are also involved in follicle development. A better understanding of all the processes involved in follicular development regulated by growth factors will develop procedures to enhance the reproductiv...

the majority of cancer treatments are invasive. gonadal injuries cause reductions in fertility which results in lack of hope for conception in cancer patients and frustration for their partners. fortunately, current advancements in cryopreservation and transplantation sciences regarding fertility preservation lead to cryostorage of gonads and preservation prior to the onset of chemo- and radiot...