Physiology

A Backup Source of Energy

See allHide authors and affiliations

Science  06 Jun 2008:
Vol. 320, Issue 5881, pp. 1262-1263
DOI: 10.1126/science.320.5881.1262d

The quality of mammalian semen is often judged by sperm motility, and the impaired movement of sperm toward egg is a common cause of infertility. Prior studies have claimed that the energy (ATP) for spermatozoan flagellar movement originates from glycolysis or from mitochondrial oxidative phosphorylation; however, the primary pathway for producing ATP may in fact differ across species. Hung et al. use the glycolysis inhibitor alpha-chlorohydrin (ACH) or oxidative phosphorylation inhibitor pentachlorophenol (PCP) to determine the source of energy in rhesus monkey sperm. ACH interfered with whiplash motility and sperm velocity, and additional assays showed that glycolysis is the major energy source for sperm motility, hyperactivation, and protein tyrosine phosphorylation. Although flagellar mitochondrial ATP did not appear to be sufficient to sustain sperm motility and hyperactivation, ATP from glycolysis or oxidative phosphorylation did support sperm capacitation and binding to the zona pellucida. — BAP

Biol. Reprod. 78, 10.1095/biolreprod.107.066357 (2008).

Navigate This Article