background: the mammalian ovary is controlled by a number of biological rhythms, which regulate the recruitment and release of mature oocytes. the main objective of this study was to investigate the role of cellular clock proteins during follicle maturation in the mouse estrous ovary. methods: immunohistochemical (ihc) studies were performed on ovaries from 50 estrous staged mice culled at two ...

BACKGROUND Primordial ovarian follicles, which are often present in the ovaries of premature ovarian failure (POF) patients or are cryopreserved from the ovaries of young cancer patients who are undergoing gonadotoxic anticancer therapies, cannot be used to generate mature oocytes for in vitro fertilization (IVF). There has been very little success in triggering growth of primordial follicles t...

The established follicle envelope of Necturus maculosus consists of a layer of follicle cells (granulosa) surrounding the developing oocyte, a layer of theca comprised of connective tissue cells, fibers, and matrix, and a layer of serosal cells. The changes in shape and fine structure of these layers during differentiation accompanying oogenesis are described. The cells and capillaries of the f...

Fluctuating feed resources to beef cows across the production cycle is a proven method for decreasing input costs; however, limiting nutrients during late gestation have been demonstrated to decrease ovarian follicle numbers in female offspring in some studies. We hypothesize that limiting nutrients to mature (Z3 yr) crossbred beef cows during the second and third trimesters would result in dau...

The ovulatory LH surge induces dramatic molecular and structural changes in follicular environment, culminating with follicle rupture and release of a mature oocyte. This review addresses the pre-LH surge events associated with the ovulatory process, such as dominant follicle differentiation and acquisition of ovulatory capacity, as well as autocrine and paracrine factors induced after the LH s...

In mammals, immature oocytes are surrounded by a layer of flattened cells. At this early stage of development, these "follicle cells" and the plasma membrane of the oocyte are in close proximity. As the oocyte matures, the follicle cells multiply and become cuboidal or radially elongated, and a jelly-like substance containing polysaccharides (1) appears between the oocyte cortex and the follicl...

The granulosa cells are believed to originate from ovarian surface epithelial mesothelium or possibly from the rete ovarii.[77] The cohort of granulosa cells that surrounds each oocyte has an oligoclonal origin, with three to five parent cells giving rise to the full complement of granulosa cells in a mature follicle.[78] Granulosa cells receive no direct blood supply, and because a basal lamin...

In a sexually mature female, primordial follicles continuously leave the arrested pool and undergo the primordial to primary follicle transition. The oocytes increase in size and the surrounding squamous pre-granulosa cells become cuboidal and proliferate to form a layer of cuboidal cells around the growing oocyte. This development of the primordial follicle commits the follicle to undergo the ...

During ovulation and luteinization in mammals a portion of the ovarian tissue undergoes extensive remodeling. The thecal framework of a mature follicle is degraded and disrupted as the ovum is released. Immediately following ovulation the fibroblasts rapidly undergo functional reorientation (a) to initiate healing at the point of rupture and (b) to meet the changing requirements for support of ...

The preovulatory follicles of the mature domestic birds are arranged in a distinct hierarchical order in the ovary. Presumably all preovulatory follicles are exposed to a daily surge of luteinizing hormone (LH), but only the largest follicle (F1) ovulates each day. This has been explained by the ability of progesterone synthesis of F1 in response to LH. In fact, progesterone contents in the fol...