Sperm capacitation is a complex process that involves a protein kinase A (PKA)-dependent tyrosine phosphorylation of proteins. We studied the time-course, the modulation and the cellular localization of the phosphorylation of the Arginine-X-X-(Serine/Threonine) motif, characteristic of PKA substrates, in sperm proteins during capacitation. There was an increased phosphorylation of 80 (p80) and ...

Gamete recognition proteins can evolve at astonishing rates and lie at the heart of reproductive isolation and speciation in diverse taxa. However, the source of selection driving this evolution remains unknown. We report on how the sperm bindin genotype influences reproductive success under natural conditions. An interaction between genotype frequency and spawning density determines how sperm ...

Glycan-protein interactions play a key role in mammalian fertilization, but data on the composition and identities of protein complexes involved in fertilization events are scarce, with the added complication that the glycans in such interactions tend to differ among species. In this study we have used a bovine model to detect, characterize and identify sperm lectins relevant in fertilization. ...

Hamster caput epididymal spermatozoa exhibit a marked 90-180 degree bend when induced to acquire progressive motility in vitro (Cornwall et al, 1988). Flagellar bending is prevented by oxidizing sperm sulfhydryl (SH) groups with diamide. In the present study, the authors examined the SH proteins involved in sperm flagellar bending using two-dimensional polyacrylamide gel electrophoresis and mon...

Oviductal sperm storage tubules (SST), located at the uterovaginal junction, are the primary site of sperm storage in turkeys. Sperm reside within these storage sites and may be released via a dynamic interaction between sperm mobility and a fluid current generated by the SST epithelial cells. In this study, aquaporins 2, 3, and 9 (proteins that form water channels in the plasmalemma of a varie...

Sperm-egg interaction was investigated in mouse eggs freed from the zona pellucida and injected with Clostridium difficile toxin B, the inhibitor of Rho family small G proteins. Toxin B reduced in a dose-dependent manner the percentage of eggs associated with sperm fusion on the surface or sperm nucleus decondensation in the ooplasm, examined by injection of a DNA-staining dye into the egg and ...

Fertilization involves cell-cell fusion of a sperm with the oocyte. This fusion restores the diploid genome, activates the oocyte, and initiates embryonic development. The identification of proteins mediating the fusion of sperm with oocyte plasma membrane (oolemma) is important to a deeper knowledge of fertilization. Defects in sperm-oocyte fusion may account for some form of human infertility...

BACKGROUND We have investigated the expression of voltage-gated sodium channels in human spermatozoa and characterized their role in sperm motility. METHODS Freshly ejaculated semen was collected from thirty normozoospermic human donors, with each donor supplying 2 different samples. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence techniques were used to detect...

Proteins known to function during cell-cell communication and exocytosis in neurons and other secretory cells have recently been reported in human sperm. Synapsins are a group of proteins that have been very well characterized in neurons, but little is known about synapsin function in other cell types. Based upon previous findings and the known function of synapsin, we tested the hypothesis tha...

The urea and guanidine hydrochloride (GuHCI) unfolding of sperm whale ferrimyoglobin and of horse ferrimyoglobin has been studied under equilibrium conditions at both neutral and acid pH. Using two spectral parameters (the Soret absorbance and the molar ellipticity at 222 nm) to monitor conformational equilibria, and various thermodynamic treatments of the resulting data, it was found that the ...