CatSper1 required for evoked Ca ²⁺ entry and control of flagellar function in sperm

CatSper family proteins are putative ion channels expressed exclusively in membranes of the sperm flagellum and required for male fertility. Here, we show that mouse CatSper1 is essential for depolarization-evoked Ca 2+ entry and for hyperactivated movement, a key flagellar function. CatSper1 is not needed for other developmental landmarks, including regional distributions of Ca V 1.2, Ca V 2.2, and Ca V 2.3 ion channel proteins, the cAMP-mediated activation of motility by [12pt]{minimal} {amsmath} {wasysym} {amsfonts} {amssymb} {amsbsy} {mathrsfs} {}{-69pt} {document} {equation*}{HCO}₃⁻{equation*}{document} , and the protein phosphorylation cascade of sperm capacitation. We propose that CatSper1 functions as a voltage-gated Ca 2+ channel that controls Ca 2+ entry to mediate the hyperactivated motility needed late in the preparation of sperm for fertilization.