Mammalian spermatozoa undergo a series of molecular and biochemical changes collectively termed capacitation prior to acquiring the ability to fertilise the oocyte. Although phosphorylation of sperm proteins on tyrosine residues has been recognised as an important component of this process, the precise relationship between the phosphorylation status of mammalian spermatozoa and their capacity f...

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...

Recent studies have demonstrated that a prostatic tripeptide similar in structure to thyrotrophin-releasing hormone (TRH) can stimulate the in-vitro capacitation and fertilizing ability of epididymal mouse spermatozoa. Therefore we have proposed that this tripeptide be referred to as fertilization promoting peptide (FPP). Using chlortetracycline fluorescence analysis and the hamster oocyte pene...

As the chemical environment of semen can have a profound effect on sperm quality, we examined the effect of pH on the motility, viability and capacitation of human sperm. The sperm in this study was collected from healthy males to avoid interference from other factors. The spermatozoa cultured in sperm nutrition solution at pH 5.2, 6.2, 7.2 and 8.2 were analyzed for sperm total motility, progre...

Pkdrej, a member of the polycystin-1 gene family, is expressed only in the male germ line. Male mice that are homozygous for a targeted mutation in the Pkdrej allele (Pkdrej(tm/tm)) are fertile in unrestricted mating trials, but exhibit lower reproductive success when competing with wild-type males in sequential mating trials and in artificial insemination of mixed-sperm populations. Following ...

Capacitation is characterized by a hyperactivated pattern of sperm motility. The acquisition of highly motility is present in the early stages of capacitation. Sperm progressive motility is one of the most important parameters for determining the suitability of semen for processing. However, previous studies have shown that some sperm showing good motility have membrane damage. The aim of our s...

The aim of this article is to review the surface molecules that are involved in capacitation/acrosomal exocytosis and zona pellucida (ZP) binding in context of tyrosine phosphorylation leading to signal transduction in human sperm. During capacitation, at least 7 proteins (200, 112, 104, 48, 42, 31 and 25 kD) are phosphorylated as studied by the 32P metabolic labeling assay, and 14 proteins (12...

The aim of this work was to study the influence of vitamin E (2mM) on capacitation and acrosome reaction of crossbred cattle bull spermatozoa. Fresh semen suspended in TALP medium (pH 7.4) was divided into four equal fractions. All fractions; control (containing TALP + spermatozoa) and the experimental [treated / untreated with ferrous ascorbate (FeAA – 150 μM FeSO4 : 750 μM ascorbic acid); sup...

Sperm capacitation is a maturation event that takes place in the female reproductive tract and is essential for fertilization. A family of phospholipid-binding proteins present in bovine seminal plasma (BSP proteins) binds the sperm membrane at ejaculation and promotes bovine sperm capacitation. Homologues of these proteins have also been isolated from boar, ram, goat, bison and stallion semina...

Capacitation is defined as the series of transformations that spermatozoa normally undergo during their migration through the female genital tract, in order to reach and bind to the zona pellucida, undergo the acrosome reaction, and fertilize the egg. During this process, extensive changes occur in all sperm compartments (head and flagellum; membrane, cytosol, cytoskeleton), factors originating...