Scientists Discover Sperm's Motility Secret

Feb 08, 2010
Scientists uncovered the secrets of the fertilization process, discovering the mechanism that makes sperm swim to the egg. This finding can lead to the development of the innovative male birth control methods and new infertility treatments.

It has been long known that sperm is motile only for a short period of time. In the male reproductive tract sperm is in a passive state or they will easily be worn out and won't be able to fertilize the egg. In order to make sperm move on, there should be the right environment. When sperm gets into female reproductive tract, the alkaline pH inside vagina makes sperm release protons, which stimulates sperm to swim to the egg.

Yuriy Kirichok, the leading researcher at the University of California, San Francisco, explains that the concentration of protons inside the sperm cell is 1,000 times higher than outside. If you open a pore, the protons will flow out and the sperm will swim. In fact, sperm flagellum, a long and thin structure, has numerous Hv1 proton channels. External factors, such as alkaline environment of the vagina or removal of zinc outside the cell make the pores open, which prompts sperm to swim.

Scientists say that the discovery of the Hv1 proton channels may help them develop novel male birth control methods. This can be done by learning how to block the molecule that activates sperm. Otherwise, scientists can find a way to stimulate sperm to move on to fertilize the egg, if the couple deals with infertility issues.

The study was published in the journal Cell, a Cell Press publication.