In the mammalian ovary, progressive activation of primordial follicles from the dormant pool serves as the source of fertilizable ova. Menopause, or the end of female reproductive life, occurs when the primordial follicle pool is exhausted. However, the molecular mechanisms underlying follicle activation are poorly understood. We provide genetic evidence that in mice lacking PTEN (phosphatase a...

Recent interest in the initial phases of ovarian follicular formation and development has lead to a number of publications in this area, most of which address the autocrine and paracrine factors involved in primordial follicle activation to primary follicle. Primordial follicle assembly (first step in follicle formation) determines the lifetime supply of primordial follicles and remains a poorl...

Neurotrophins are growth factors that are known to have a role in promoting cell survival and differentiation. The focus of the current study is to examine the role of neurotrophins in regulating ovarian primordial follicle development. Ovaries from 4-day old rats were placed into organ culture and cultured for 10 days in the absence or presence of neurotrophin-3 (NT3), brain-derived neurotroph...

With increasing numbers of young female cancer survivors following chemotherapy, chemotherapy-induced fertility loss must be considered. Menstrual disorder and infertility are of particular concern in female cancer patients. We showed that treatment with the alkylating agent cyclophosphamide (CTX) could cause severe primordial follicle loss and growing follicle apoptosis, resulting in loss of o...

Primordial follicle formation represents a critical phase of the initiation of embryonic reproductive organ development, while the primordial follicle transition into primary follicle determines whether oestrus or ovulation will occur in female animals. To identify molecular mechanism of new proteins which are involved in ovarian development, we employed 2D-DIGE to compare the protein expressio...

Ultrastructural and morphometric changes in oocyte and surrounding granulosa cells during armadillo follicular growth are described. Primordial, intermediary, early and late primary, secondary, tertiary and preovulatory Graafian follicles were found. From primordial to Graafian follicle, granulosa cells increase in height, become multilayered while fluid-filled spaces arise among them in the te...

BACKGROUND C-src is an evolutionarily conserved proto-oncogene that regulates cell proliferation, differentiation and apoptosis. In our previous studies, we have reported that another proto-oncogene, c-erbB2, plays an important role in primordial follicle activation and development. We also found that c-src was expressed in mammalian ovaries, but its functions in primordial follicle activation ...

In mammalian ovaries, a fixed population of primordial follicles forms during the perinatal stage and the oocytes contained within are arrested at the dictyate stage of meiotic prophase I. In the current study, we provide evidence that the level of cyclic AMP (cAMP) in oocytes regulates oocyte meiotic prophase I and primordial folliculogenesis in the perinatal mouse ovary. Our results show that...

In female mammals, primordial follicles consist of two types of cells, namely, oocytes and pregranulosa cells that surround the oocytes. The size of the primordial follicle pool determines the reproductive ability of female mammals. However, the underlying mechanisms controlling primordial follicle assembly remain unclear. In this study, we show that oocyte-derived Janus kinase (JAK) signaling ...

BACKGROUND In mammalian females, reproductive capacity is determined by the size of the primordial follicle pool. During embryogenesis, oogonia divide mitotically but cytokinesis is incomplete so oogonia remain connected in germ cell cysts. Oogonia begin to enter meiosis at 13.5 days postcoitum in the mouse and over several days, oocytes progress through the stages of meiotic prophase I arresti...