Polo-like kinase 1 (PLK1) orchestrates multiple events of cell division. Although PLK1 function has been intensively studied in centriole-containing and rapidly cycling somatic cells, much less is known about its function in the meiotic divisions of mammalian oocytes, which arrest for a long period of time in prophase before meiotic resumption and lack centrioles for spindle assembly. Here, usi...

The role of the nuclear phosphoinositide (PI) cycle during meiotic resumption in mouse oocytes was examined. First, using indirect immunofluorescence staining with specific monoclonal antibodies (mAbs) against elements of this cycle, the presence of inositol trisphosphate receptors (IP3Rs) (IP3R-1 or IP3R-3) or phosphoinositide-phospholipase (PLC) isoforms (PLC beta 1 or PLC gamma 1) was monito...

Ovarian follicle maturation (OFM), including the resumption of meiosis in oocyte, is under hormonal regulation. Insulin-like growth factors (IGF) have been shown to participate regulation OFM with species-specific actions teleost fishes. In present study, vitro treatment rainbow trout ovarian follicles recombinant human insulin-like factor-1 (rhIGF1) or rhIGF2 did not induce germinal vesicle br...

In the process of oocyte maturation, gonadotrophins are believed as main stimulators for oocyte meiosis resumption. However, which gonadotrophin (i.e. FSH or LH) is the key hormone in this process is still unknown. This study indicated a close relationship between LH and FSH on activating meiotic maturation of oocyte in vitro. FSH efficiently induced oocyte meiosis at concentration of 50 IU/L, ...

Fertilization of metaphase II-arrested mouse eggs results in resumption of meiosis and a decrease in both cdc2/cyclin B kinase and MAP kinase activities; the decrease in cdc2/cyclin B kinase activity precedes the decrease in MAP kinase activity. Cycloheximide treatment of metaphase II-arrested mouse eggs also results in resumption of meiosis but bypasses the fertilization-induced Ca2+ transient...

BACKGROUND Luteinizing hormone (LH) regulation of the ligand, natriuretic peptide precursor type C, and its receptor, natriuretic peptide receptor 2 (NPR2), is critical for oocyte maturation; however, the mechanism is not fully understood. Macrophage colony-stimulating factor (M-CSF) has recently been shown to be involved in oocyte maturation and ovulation. In the present study we determined wh...

Mammalian ovary is a dynamic organ that is responsible for the production of competent oocytes required for successful fertilization and early embryonic development [1,2]. The meiotic competency folliocular is achieved within the follicular environment during final stages of folliculogenesis [3-7]. The achievement of meiotic competency starts in diplotene arrested oocytes, possessing germinal v...