Activins and estrogens participate in regulating the breakdown of ovarian germ cell nests and follicle assembly in mammals. In 1994, our group reported elevated frequencies of abnormal, multioocytic ovarian follicles in 6 month old, environmental contaminant-exposed female alligators after gonadotropin challenge. Here, we investigated if maternal contribution of endocrine disrupting contaminant...

BACKGROUND Polycystic ovarian syndrome (PCOS) is a heterogeneous endocrine disorder affecting women of reproductive age. The syndrome is characterized by a combination of polycystic ovarian morphology, clinical features and biochemical indices. The objective of this prospective observational study was to investigate the relationship between the total ovarian volume and the ovarian stromal volum...

Ovarian follicle development is a complex process that begins with the establishment of what is thought to be a finite pool of primordial follicles and culminates in either the atretic degradation of the follicle or the release of a mature oocyte for fertilization. This review highlights the many advances made in understanding these events using transgenic mouse models. Specifically, this revie...

The mammalian ovarian follicle consists of a multilayered complex of somatic cells that surround the oocyte. A signal from the follicle cells keeps the oocyte cell cycle arrested at prophase of meiosis I until luteinizing hormone from the pituitary acts on the follicle cells to release the arrest, causing meiosis to continue. Here we show that meiotic arrest can be released in mice by microinje...

During reproductive life in the female, there is a continuous flow of growth, maturation and demise of ovarian follicles, unless pregnancy occurs. Although ovarian function is primarily controlled by the hypothalamus-pituitary-axis, there is no doubt that a hormonal microenvironment specific for each individual follicle is established, that finally determines whether a follicle ovulates and bec...

BACKGROUND There is substantial evidence both in humans and in animals that a prolonged reduction in plasma thyroid hormone concentration leads to reproductive problems, including disturbed folliculogenesis, impaired ovulation and fertilization rates, miscarriage and pregnancy complications. The objective of the present study is to examine the consequences of chronic hypothyroidism, induced in ...

Fertility in mammals is dependant on females having an adequate primordial follicle pool to supply oocytes for fertilization. The formation of primordial follicles is called ovarian follicular assembly. In rats and mice progesterone and estradiol have been shown to inhibit follicle assembly with assembly occurring after birth when the pups are removed from the high-steroid maternal environment....

OBJECTIVE To investigate the possible influence of follicular maturation and luteinization on anti-müllerian hormone (AMH) secretion and the relationship between per-follicle AMH levels, ovarian follicular status, and responsiveness to controlled ovarian hyperstimulation (COH). DESIGN Prospective study. SETTING University hospital in France. PATIENT(S) Thirty seven in vitro fertilization/...

An ovarian follicle is composed of an oocyte and surrounding theca and granulosa cells. Oocytes are stored in an arrested state within primordial follicles until they are signaled to re-initiate development by undergoing primordial-to-primary follicle transition. Previous gene bionetwork analyses of primordial follicle development identified a number of critical cytokine signaling pathways and ...

The mechanism by which one or more dominant ovarian follicles continue development while other subordinate follicles regress is not known. The mitogen activated protein kinases (MAPKs) are a group of kinases that are activated by hormonal factors and form a cascade of processes that regulate cell growth, division and differentiation. The aim of the present experiment was to characterise the pre...