Penetration of cervical mucus by spermatozoa was observed in cycling and infertile women, in women on sequential or combination oral contraceptive medication, and in women with an IUD in situ. _Sperm penetration of cervical mucus varied from women not using contraceptives and from infertile women, to patients taking sequential conception control pills. In cycling women penetration was low in th...

At fertilization, spermatozoa bind to the zona pellucida (ZP1, ZP2, ZP3) surrounding ovulated mouse eggs, undergo acrosome exocytosis and penetrate the zona matrix before gamete fusion. Following fertilization, ZP2 is proteolytically cleaved and sperm no longer bind to embryos. We assessed Acr3-EGFP sperm binding to wild-type and huZP2 rescue eggs in which human ZP2 replaces mouse ZP2 but remai...

Human sperm have been documented to display apoptosis-like features such as externalization of phosphatidylserine (EPS), disruption of the transmembrane mitochondrial potential (MMP) and activation of caspases. Our aim was to evaluate possible association between activation of the apoptosis cascade in human sperm and its oocyte penetration capacity using the zona free hamster oocyte penetration...

The aim of this study was to assess the predictive value of the hypoosmotic sperm swelling test. Good correlations were observed between the percentage of spermatozoa undergoing swelling and the percentage motility both in normal (r = 0.68; p < 0.001) and infertile patients (r = 0.65; p < 0.001). In contrast, sperm swelling did not significandy correlate either with sperm oocyte fusion (assesse...

Fertilization comprises oligosaccharide-mediated sperm-egg interactions, including sperm binding to an extracellular egg envelope, sperm penetration through the envelope, and fusion with an egg plasma membrane. We show that Xenopus dicalcin, an S100-like Ca(2+)-binding protein, present in the extracellular egg envelope (vitelline envelope (VE)), is a suppressive mediator of sperm-egg interactio...

The objective of this research was to estimate the optimal timing for fertilization to achieve proper embryonic development of in vitro-matured bovine oocytes. First, cumulus-oocyte complexes were subjected to in vitro maturation (IVM) for 14-22 hr. The timing when 50% of oocytes reached metaphase II stage was estimated to be 17.5 hr after IVM start. Next, using oocytes subjected to IVM for 12-...

Using homologous recombination, we have previously produced male mice carrying a disruptive mutation (Acr-/-) in the acrosin gene. Although Acr-/- mouse sperm lacking the acrosin protease activity still penetrated the zona pellucida and fertilized the egg, the mutant sperm exhibited a delay in penetration of the zona pellucida solely at the early stages after insemination. To further elucidate ...