During mammalian fertilisation, the zona pellucida (ZP) matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction (AR) in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in human...

AIM To investigate the possible functions of human sperm membrane protein (hSMP-1) in the process of fertilization. METHODS A 576-bp cDNA fragment of HSD-1 gene coding for the extracellular domain of hSMP-1 was cloned and expressed. The localization of this protein on human and mouse sperm was determined by indirect immunofluorescent staining by using anti-recombinant hSMP-1 (anti-rhSMP-1) an...

Recently, the conception rates after artificial insemination have been pointed out to decline continuously. To overcome this problem, the control of frozen and thawed sperm quality is required. However, the mechanism of bovine sperm functional regulation is still largely unknown. In mammals, the ejaculated sperm are capable of showing fertilizing ability during migration in the female reproduct...

Fertilization occurs after the completion of the sperm acrosome reaction, a secretory event that is triggered during gamete adhesion. ZP3, an egg zona pellucida glycoprotein, produces a sustained increase of the internal Ca(2+) concentration in mouse sperm, leading to acrosome reactions. Here we show that the sustained Ca(2+) concentration increase is due to the persistent activation of a Ca(2+...

The sperm acrosome reaction takes place in response to progesterone and zona pellucida. Progesterone may act on more than one type of surface receptor, of which one is a gamma-aminobutyric acid (GABA) type A-like receptor. Although there is direct evidence of GABA initiation of mouse sperm acrosome reaction, there are conflicting results regarding GABA-induced exocytosis in human spermatozoa. W...

BACKGROUND ICSI bypasses the sperm-oolemma interactions that, in normal fertilization, depend on completion of the acrosome reaction. Morphological changes in the acrosomes of sperm in the ooplasm were therefore examined following IVF and ICSI using pig gametes. METHODS In-vitro-matured porcine oocytes were used for ICSI or IVF. Oocytes were then stained with fluorescein isothiocyanate-conjug...

The intact acrosome of the Mytilus edulis spermatozoon consists of a conical vesicle, the basal side of which is deeply invaginated so that the whole vesicle forms a sheath around a very slender axial rod, about 2.7 micro long, inserted in a tube passing through the nucleus. The annular base of the acrosomal vesical is filled with a homogeneous substance; the outer wall of the vesicle is lined ...

Capacitation and the acrosome reaction are key phenomena in mammalian fertilization. These phenomena were found more than 60 years ago. However, fundamental questions regarding the nature of capacitation and the timing of the acrosome reaction remain unsolved. Factors were postulated over time, but as their roles were not verified by gene-disruption experiments, widely accepted notions concerni...

Heparin binding proteins (HBPs) are produced by accessory glands. These are secreted into the seminal fluid, bind to the spermatozoa at the time of ejaculation, favour capacitation, acrosome reaction, and alter the immune system response toward the sperm. The present study was conducted with an objective to assess the effect of purified seminal plasma-HBPs (SP-HBPs) on cross bred cattle bull sp...