Proteins involved in reproductive fitness have evolved unusually rapidly across diverse groups of organisms. These reproductive proteins show unusually high rates of amino acid substitutions, suggesting that the proteins have been subject to positive selection. We sought to identify seminal fluid proteins experiencing adaptive evolution because such proteins are often involved in sperm competit...

Sperm membranes have an unusual lipidic composition which is distinct from those of mammalian somatic cells. They have high levels of plasmalogens, a kind of ether-linked lipids, and a high content of polyunsaturated fatty acyl groups. Plasmalogens may form non-diffusible membrane regions or domains, whereas polyunsaturated ethanolamine plasmalogens are known to destabilize the lipidic bilayer....

A significant percentage of young men are infertile and, for the majority, the underlying cause remains unknown. Male infertility is, however, frequently associated with defective sperm motility, wherein the sperm tail is a modified flagella/cilia. Conversely, a greater understanding of essential mechanisms involved in tail formation may offer contraceptive opportunities, or more broadly, thera...

Gamete-recognition proteins determine whether sperm and eggs are compatible at fertilization, and they often evolve rapidly. The source of selection driving the evolution of these proteins is still debated. It has been suggested that sexual conflict can result in proliferation of genetic variation and possibly linkage disequilibrium between sperm and egg proteins. Empirical evidence suggests th...

Little is known about the molecular impact of in vivo exposure to endocrine disruptors (EDs) on sperm structures and functions. We recently reported that the lifelong exposure of rats to the antiandrogenic compound vinclozolin results in low epididymal weight, changes in sperm kinematic parameters, and immature sperm chromatin condensation, together with the impairment of several fertility end ...

Semen evaluation via traditional light microscopy provides useful information about sperm motility and morphology, yet it has a limited utility in predicting reproductive performance due to its subjective nature and inconsistency among technicians and laboratories. Furthermore, not all sperm abnormalities are detectable with standard light microscopy. As a result, flow cytometric evaluation usi...

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...

Recent data from several laboratories have provided evidence that the newly fertilized oocyte inherits epigenetic signals from the sperm chromatin that are required for proper embryonic development. For the purposes of this review, the term epigenetic is used to describe all types of molecular information that are transmitted from the sperm cell to the embryo. There are at least six different f...

The presence and role of c-ras proteins were investigated in mature human sperm cells. The v-H-ras monoclonal antibody (mAb) against the c-ras protein, p21, reacted specifically with the acrosomal region of methanol-fixed as well as unfixed-live capacitated and non-capacitated human sperm cell in the indirect immunofluorescence technique. The v-H-ras mAb predominantly recognized c-ras protein o...