BACKGROUND The stage of folliculogenesis at which the human zona pellucida (ZP) is initiated and the cells responsible for the origin of the ZP continue to be controversial. This study characterizes the development of the ZP during human folliculogenesis using ovarian samples donated from patients requesting ovarian storage. METHODS Follicles (from n = 18 patients, 14-40 years old) within fre...

The aim of the present study was to investigate the effects of activin-A and follistatin on in vitro primordial and primary follicle development in goats. To study primordial follicle development (experiment 1), pieces of ovarian cortex were cultured in vitro for 5 days in minimal essential medium (MEM) supplemented with activin-A (0, 10 or 100 ng/ml), follistatin (0, 10 or 100 ng/ml) or combin...

The study of human ovarian tissue transplantation and cryopreservation has advanced significantly. Autotransplantation of human pre-antral follicles isolated from cryopreserved cortical tissue is a promising option for the preservation of fertility in young cancer patients. The purpose of the present study was to reveal the effect of vitrification after low-temperature transportation of human p...

Previous studies have reported many discrepancies about the best type and concentration of cryoprotective agents (CPAs) and biological variability among various pre-antral follicle classes after cryopreservation of ovarian tissue. The aim of this study was to investigate the impacts of some synthetic polymers on histological characteristics of different types of pre-antral follicles after bovin...

Notch signaling directs cell fate during embryogenesis by influencing cell proliferation, differentiation, and apoptosis. Notch genes are expressed in the adult mouse ovary, and roles for Notch in regulating folliculogenesis are beginning to emerge from mouse genetic models. We investigated how Notch signaling might influence the formation of primordial follicles. Follicle assembly takes place ...

objective: the role of wnt signaling and its antagonist; secreted frizzled related protein type 4 (sfpr4) was reported in rodent ovarian follicular development. this study examines immunolocalization of sfrp4 in ovaries of polycystic ovary (pco) rat model and evaluates its role in follicular growth arrest and its premature differentiation. materials and mathods: pco was induced with daily admin...

Background: Growth differentiation factor -9B (GDF-9B) is an oocyte derived growth factor, this protein is essential for development of ovarian follicles and act mainly by binding to its receptor on the surface of granulosa cells. The effect of this factor on the growth of follicles in various developmental stages particularly primordial and primary follicles is unknown. The aim of this study w...

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...

www.landesbioscience.com Cell Cycle 3353 The pool of ovarian primordial follicles is established during embryonic development in humans, or after birth in rodents, and serves as the source of developing follicles and fertilizable ova for the entire length of female reproductive life. Once the pool of primordial follicles has been exhausted, menopause occurs in women around 50 y old. With modern...

Primordial ovarian follicles in mice form when somatic cells surround individual oocytes. We show that lack of Nobox, an oocyte-specific homeobox gene, accelerates postnatal oocyte loss and abolishes the transition from primordial to growing follicles in mice. Follicles are replaced by fibrous tissue in female mice lacking Nobox in a manner similar to nonsyndromic ovarian failure in women. Gene...