Acrosomal alkalinization occurs during human sperm capacitation.

Mammalian sperm capacitation is a prerequisite for successful fertilization. Capacitation involves biochemical and physiological modifications of sperm as they travel through the female reproductive tract. These modifications prepare the sperm to undergo the acrosome reaction (AR), an acrosome vesicle exocytosis that is necessary for gamete fusion.

Acrosome reaction and Ca²⁺ imaging in single human spermatozoa: new regulatory roles of [Ca²⁺]i.

The spermatozoa acrosome reaction (AR) is essential for mammalian fertilization. Few methods allow visualization of AR in real time together with Ca²⁺ imaging. Here, we show that FM4-64, a fluorescent dye used to follow exocytosis, reliably reports AR progression induced by ionomycin and progesterone in human spermatozoa.

Acute slices of mice testis seminiferous tubules unveil spontaneous and synchronous Ca2+ oscillations in germ cell clusters.

Spermatogenic cell differentiation involves changes in the concentration of cytoplasmic Ca(2+) ([Ca(2+)]i); however, very few studies exist on [Ca(2+)]i dynamics in these cells. Other tissues display Ca(2+) oscillations involving multicellular functional arrangements. These phenomena have been studied in acute slice preparations that preserve tissue architecture and intercellular communications.