Cumulus expansion and oocyte maturation are central processes in ovulation. Knowledge gained from rodent and other mammalian models has revealed some of the molecular pathways associated with these processes. However, the equivalent pathways in humans have not been thoroughly studied and remain unidentified. Compact cumulus cells (CCs) from germinal vesicle cumulus oocyte complexes (COCs) were ...

MicroRNAs (miRNAs) have been improved to regulate oocyte development in a cell- or stage-specific manner. In this study, we aimed to clarify microRNA-224's (miR-224) role in cumulus cells (CCs), to find out whether a change level of miR-224 in CCs could influence the maturation of oocyte. We found that overexpression of miR-224 of CCs led to the impairment of cell expansion, along with a decrea...

in order to determine the most effective hormones on the in vitro oocyte maturation (germinal vesicle breakdown - gvbd) in a hybrid sturgeon bester, ovarian follicles were incubated at the migratory nucleus stage in the presence of several steroids, gonadotropin preparations and forskolin. occurrence of gvbd and 17,20β-dihydroxy-4-pregnen-3 -one (dhp) production were followed during an expe...

Final oocyte maturation using GnRH-agonist trigger in a GnRH-antagonist protocol is increasingly common, as ovarian hyperstimulation syndrome is almost completely avoided. However, this approach might lead to reduced pregnancy rates due to severe luteolysis. This proof of concept study evaluated the extend of luteolysis by measuring progesterone levels 48 hours after oocyte retrieval in 51 pati...

Citrinin is one of the mycotoxins and has been shown to have various toxic effects in animals and humans. Although previous study showed the toxic effects of citrinin on the female reproductive system, especially on oocyte maturation, however, the causes or mechanism of citrinin on oocyte quality is unclear. In present study we deeply investigated this topic. We found thatcitrinin toxin exposur...

the aim of the present study was to find the effects of pre and post vitrification taxol treatment on bovineimmature cumulus oocyte complexes (cocs). bovine ovaries were collected from the local slaughterhousein a container with 30-37°c physiologic saline and supplemented with antibiotics. the grade a aspiratedcocs were assigned to 6 experimental groups; the 1st group was control (n=100) in whi...

Fully grown Xenopus oocytes can remain in their immature state essentially indefinitely, or, in response to the steroid hormone progesterone, can be induced to develop into fertilizable eggs. This process is termed oocyte maturation. Oocyte maturation is initiated by a novel plasma membrane steroid hormone receptor. Progesterone brings about inhibition of adenylate cyclase and activation of the...

Delayed ovulation and delayed fertilization can lead to reduced developmental competence of the oocyte. In contrast to the consequences of postovulatory aging of the oocyte, hardly anything is known about the molecular processes occurring during oocyte maturation if ovulation is delayed (preovulatory aging). We investigated several aspects of oocyte maturation in two models of preovulatory agin...

Fertilization in the female reproductive tract depends on intercellular signaling mechanisms that coordinate sperm presence with oocyte meiotic progression. To achieve this coordination in Caenorhabditis elegans, sperm release an extracellular signal, the major sperm protein (MSP), to induce oocyte meiotic maturation and ovulation. MSP binds to multiple receptors, including the VAB-1 Eph recept...