A tiny electrode captures, for the first time, the electrical activity of a single sperm cell. This technically difficult maneuver provides the first glimpse of the currents that flow across the sperm's outer membrane as calcium enters. This influx -- through a calcium channel called CatSper, found only in the tails of mature sperm -- is what gives sperm the burst of swimming power needed to reach the egg. Mice that are deficient in CatSper are infertile; their sperm are less motile and show less directed movement. Hydra Biosciences (Cambridge, MA) is now looking for ways to block the CatSper channel to create a male contraceptive. Image courtesy Yuriy Kirichok, PhD, Betsy Navarro, PhD, and David Clapham, MD, PhD.
Note: The colors shown are not the true colors of the cells, and the photograph has been
modified and enhanced for clarity.
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