Mammalian sperm must hyperactivate in order to fertilize oocytes. Hyperactivation is characterized by highly asymmetrical flagellar bending. It serves to move sperm out of the oviductal reservoir and to penetrate viscoelastic fluids, such as the cumulus matrix. It is absolutely required for sperm penetration of the oocyte zona pellucida. In order for sperm to hyperactivate, cytoplasmic Ca(2+) l...

CatSpers are calcium (Ca(2+)) channels that are located along the principal piece of mammalian sperm flagella and are directly linked to sperm motility and hyperactivation. It has been observed that Ca(2+) entry through CatSper channels triggers a tail to head Ca(2+) propagation in mouse sperm, as well as a sustained increase of Ca(2+) in the head. Here, we develop a mathematical model to inves...

Background: Normal sperm function depends on appropriate intracellular calcium (Cai2+) and reactive oxygen species (ROS) levels. Calcium activates NADPH oxidase-5 (NOX5) that leads to ROS generation. The calcium channel of sperm (CatSper) is activated by progesterone and intracellular alkalization. Herein, the interactive role of CatSper, Hv1 channels, and NOX5 enzyme on Cai2+ and ROS generatio...

BACKGROUND CatSper1-4 are a unique family of sperm cation channels, which are exclusively expressed in the testis and play an important role in sperm motility and male fertility. Despite their vital role in male fertility, almost nothing is known about the factors regulating their expression. Here, we investigated the effects of selenium (Se) on the expression of CatSper genes and sperm paramet...

CatSper channels are essential for hyperactivity of sperm flagellum, progesterone-mediated chemotaxis and oocyte fertilization. Catsper genes are exclusively expressed in the testis during spermatogenesis, but the function and regulation of the corresponding promoter regions are unknown. Here, we report the cloning and characterization of the promoter regions in the human and murine Catsper1 ge...

Ion channels control the sperm ability to fertilize the egg by regulating sperm maturation in the female reproductive tract and by triggering key sperm physiological responses required for successful fertilization such as hyperactivated motility, chemotaxis, and the acrosome reaction. CatSper, a pH-regulated, calcium-selective ion channel, and KSper (Slo3) are core regulators of sperm tail calc...