Development of animal germ cells depends critically on continuous contact and communication with the somatic compartment of the gonad. In females, each oocyte is enclosed within a follicle, whose somatic cells supply nutrients that sustain basal metabolic activity of the oocyte and send signals that regulate its differentiation. This maternal microenvironment thus plays an indispensable role in...

BACKGROUND Failed fertilization occurs in 2-3% of ICSI cycles and is mainly due to lack of oocyte activation. Heterologous ICSI of patient's sperm in mouse oocytes allows discrimination between sperm- and oocyte-related aetiologies of activation failure. Assisted oocyte activation (AOA) by Ca-ionophore treatment can initiate fertilization in subsequent therapeutic ICSI. We report on diagnosis a...

It has been known that EGF-like factor secreted from LH-stimulated granuloma cells acts on granulosa cells and cumulus cells to induce ovulation process. Granulosa cells are changed the morphology with differentiating cell functions to produce progesterone. Cumulus cells are detached to make a space between the cells to accumulate hyaluronan rich matrix. LH also changes extracellular matrix (EC...

The cryopreservation of immature GV oocytes by vitrification is offering attractive perspectives, since they represent an important pool of germ cells for women undergoing IVM cycles, or at risk of infertility for OHSS or PCOs, particularly those poor responders to gonadotropin stimulation, or in case of cancer. Therefore, it becomes necessary to optimize both cryopreservation technique as well...

The zona pellucida (ZP) is a highly organized extracellular coat that surrounds all mammalian eggs. The mouse egg ZP is composed of three glycoproteins, called mZP1-3, that are synthesized, secreted, and assembled into a ZP exclusively by growing oocytes. Here, we microinjected epitope-tagged (Myc and Flag) cDNAs for mZP2 and mZP3 into the germinal vesicle (nucleus) of growing oocytes isolated ...

background: in general, 15% of oocytes collected in art cycles are immature. these oocytes may be cryopreserved further for use in in-vitro maturation (ivm) program. objective: the aim of this study was to determine maturation capacity, morphometric parameters and morphology of human immature oocytes in both fresh ivm (fivm) and vitrified-ivm (vivm) oocytes. materials and methods: 93 women who ...

The perivitelline space is the gap between the plasma membrane and the zona pellucida of the oocyte. Although not present in the oocytes in the germinal vesicle stage, the perivitelline space is known to start forming when meiotic maturation resumes and to enlarge in matured oocytes at the metaphase II stage (Kaufman et al., 1989; Okada et al., 1993). Recently, it has been suggested that there ...