Reproductive biologists have identified the mechanism that triggers sperm's race to the egg, reports a study in Cell today.
By measuring the electrical current passing through the sperm cell membrane, researchers at the University of California, San Francisco, identified a channel that releases a flood of protons from a sperm cell, initiating its trip up the fallopian tubes and on to the egg. "Not many people think about electricity when they talk about sperm cells. It's a major advance in the field," said linkurl:Dejian Ren,; a physiologist at the University of Pennsylvania who was not involved in the study. "This is the first time someone actually recorded the cellular process in a human sperm." While inside the testes, sperm remain immobile. But upon ejaculation, when sperm enter the vagina, their intracellular pH...
(Blue, nucleus; red, mitochondria; green, Hv1
protein localized in the sperm flagellum)