Among the numerous anti-sperm monoclonal antibodies generated in our laboratory, HS-33 was shown to react with a conserved antigen on the acrosome of spermatozoa from human and mouse. By using indirect immunofluorescent assay, it was demonstrated that HS-33 did not bind to live human sperm. However, this antibody was found to react with the methanol-fixed acrosome-intact, but not with acrosome-...

We have developed an assay for detecting the acrosome reaction in mouse sperm using chlortetracycline (CTC) as a fluorescent probe . Sperm known to be intact with nonreacted acrosomes show CTC fluorescence in the presence of Ca" over the anterior portion of the sperm head on the plasma membrane covering the acrosome . Sperm which have undergone the acrosome reaction do not show fluorescence on ...

Soluble N-ethylmalameide-sensitive factor attachment protein receptor (SNARE) proteins are present in mammalian sperm and could be involved in critical membrane fusion events during fertilization, namely the acrosome reaction. Vesicle-associated membrane protein/synaptobrevin, a SNARE on the membrane of a vesicular carrier, and syntaxin 1, a SNARE on the target membrane, as well as the calcium ...

Spermatozoon acrosome reaction is an exocytotic event of the utmost importance for the development of mammalian fertilisation. Current evidence shows that the triggering of the acrosome reaction (AR) could be regulated by the action of diverse compounds, namely, metabolites, neurotransmitters and hormones. The aim of the present review is to describe the modulating effects of several compounds ...

High step concentrations of progesterone may stimulate various sperm physiological processes, such as priming and the acrosome reaction. However, approaching the egg, spermatozoa face increasing concentrations of the hormone, as it is secreted by the cumulus cells and then passively diffuses along the cumulus matrix and beyond. In this context, several questions arise: are spermatozoa sensitive...

BACKGROUND Human egg is enveloped by a glycoproteinaceous matrix, zona pellucida (ZP), responsible for binding of the human spermatozoa to the egg and induction of acrosomal exocytosis in the spermatozoon bound to ZP. In the present manuscript, attempts have been made to delineate the downstream signalling components employed by human ZP to induce acrosome reaction. METHODS Heat-solubilized h...

Two processes, namely capacitation and acrosome reaction, are of fundamental importance in the fertilization of oocyte by spermatozoon. Physiologically occurring in the female genital tract, capacitation is a complex process, which renders the sperm cell capable for specific interaction with the oocyte. During capacitation, modification of membrane characteristics, enzyme activity and motility ...

The present was conducted to separate heparin binding proteins (HBP) of capacitated sperm extracts and determine their relationship with acrosome reaction and semen fertility of bulls (n=30). Fourteen immunoreactive bands in capacitated spermatozoa of bulls (135, 100, 75, 70, 65, 55, 48, 45, 33, 31, 26, 24, 20 and 18 kDa) were detected in western blots following incubation with anti-HBP antibod...