sperm seek the heat

Sperm cells act like heat-seeking missiles when it comes to locating an unfertilized egg, according to a paper published in the February Nature Medicine. The egg tends to lie in a spot around 2 degrees Celsius warmer than the place where sperm begin their final journey through the female genital tract. Sperm can sense this temperature difference and use it to navigate their way, reports Michael Eisenbach of the Weizmann Institute in Israel. Once in the correct vicinity, the sperm are able to follow chemical attractants released by the egg. Eisenbach tested rabbit and human sperm in a chamber built to simulate a fallopian’s tube temperature gradient, and some of the sperm exhibited a clear preference for swimming toward the warmer area. Eisenbach’s experiments also indicated that only the small percentage of sperm that are fully mature — the ones most likely to actually penetrate the egg — can sense both the temperature gradient and the chemical signals needed to reach the egg.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 2/11/2003.
This entry was posted in boston globe, news briefs. Bookmark the permalink.