E. Delamirande et al., CAPACITATION AS A REGULATORY EVENT THAT PRIMES SPERMATOZOA FOR THE ACROSOME REACTION AND FERTILIZATION, Molecular human reproduction, 3(3), 1997, pp. 175-194
Capacitation is defined as the series of transformations that spermato
zoa normally undergo during their migration through the female genital
tract, in order to reach and bind to the zona pellucida, undergo the
acrosome reaction, and fertilize the egg. During this process, extensi
ve changes occur in all sperm compartments (head and flagellum; membra
ne, cytosol, cytoskeleton), factors originating from epididymal fluid
and seminal plasma are lost or redistributed and membrane lipids and p
roteins are reorganized; ion fluxes induce biochemical modifications a
nd controlled amounts of reactive oxygen species are generated; sperma
tozoa develop hyperactivated motility; and complex signal transduction
mechanisms are initiated. The main purpose of capacitation is to ensu
re that spermatozoa reach the eggs at the appropriate time and in the
appropriate state to fertilize these eggs, by finely controlling the r
ate of the changes necessary to prime spermatozoa and by activating al
l the mechanisms needed for the subsequent acrosome reaction. The reve
rsibility of some of the mechanisms leading to sperm capacitation may
therefore be a very important aspect of the fine regulation and perfec
t timing of this process.