The extracellular coat, or zona pellucida, of mammal ian eggs contains species-specific receptors to which sperm bind as a prelude to fertilization. In mice, ZP3, one of only three zona pellucida glycoproreins, serves as sperm receptor. Acrosome-intact, but not acrosome-reacted, mouse sperm recognize and interact with specific O-linked oligosaccharides of ZP3 resulting in sperm-egg binding. Bin...

A typical mammalian egg is surrounded by an outer layer of about 3,000 cumulus cells embedded in an extracellular matrix rich in hyaluronic acid. A current, widely proposed model is that the fertilizing sperm, while it is acrosome intact, passes through the cumulus cell layer and binds to the egg zona pellucida. This current model lacks a well-supported explanation for how sperm penetrate the c...

This study was carried out to obtain informations regarding the effect of N-acetyl-D-glucosamine in the LEY (lactoseegg yolk) diluent according to incubation time in 5 ml maxi-straw and the effects of freezing rate, thawing temperature and thawing time in the LEN (lactose-egg yolk and N-acetyl-D-glucosamine) diluent on acrosome morphology and motility of frozen-thawed boar sperm. The study show...

BACKGROUND The presence of small membranous particles characterizes the male genital fluids of different mammalian species. The influence of semen vesicles, denominated prostasomes, on sperm functional properties has been well documented in humans, but their biological activity is scarcely known in other species. The present work investigated prostasome-like vesicles in pig semen for their abil...

We describe a solid-phase assay that has permitted further analysis of zona pellucida glycoprotein, ZP3, as sperm receptor and acrosome reaction-inducer during fertilization in mice. The assay employs silica beads that contain epoxy groups to which purified, mouse oocyte ZP3 is covalently linked (ZP3-beads). ZP3-beads were characterized, e.g. by whole-mount autoradiography and flow cytofluorome...

The close connection of the acrosome of the animal sperm with the Golgi apparatus was first suggested by Bowen' in 1923, who stated that the acrosomal material might be "secreted" from the Golgi apparatus. While his cytological studies seem to support the concept that the acrosome is derived from the Golgi apparatus, the staining methods employed do not allow any conclusions as to the chemical ...

To achieving high efficiency in sheep, ram sperm must have fertilization ability. Quercetin, a potent antioxidant, has been shown to positive effect on semen different species. This study aims improve the of Merino using quercetin. The ejaculates collected from rams were used for dilution (sperm density ≥ 3×109 spermatozoa/ml, motility 75%). Tris diluent was dilute semen. divided into 4 equal v...

OBJECTIVE To investigate the role of the cumulus cells and the cumulus matrix in affecting the penetrability, morphology, acrosome reaction, and motility of human spermatozoa penetrating the cumulus oophorus. DESIGN Controlled experimental laboratory study. SETTING University gynecology unit. PATIENT(S) Women undergoing assisted reproduction treatment and men visiting the subfertility cli...

BACKGROUND Lead remains in high levels in the environment and is known to reduce fertility in animal models, but a direct link between lead exposures and human infertility has not yet been established. METHODS In a prospective, double-blind study of the metal ion levels and sperm function, semen was obtained from partners of 140 consecutive women undergoing their first IVF cycle. Lead in semi...

Mammalian spermatozoa undergo capacitation and acrosome reaction in order to fertilize the egg. The PKC-ERK1/2 pathway plays an important role in human spermatozoa motility, capacitation and the acrosome reaction. Here we demonstrate that ERK1/2 phosphorylates proAKAP4 on Thr265 in human spermatozoa in vitro and in vivo. Cyclic AMP (cAMP) had no effect on ERK1/2 activity in human spermatozoa, b...