A protein that nematode sperm cells use for getting around also stimulates egg
maturation and ovulation in the worms, according to a report in March 16 Science.
Triggering ovulation with major sperm protein, or MSP, ensures that eggs aren’t
released at a time when there’s no sperm around to fertilize them, explains
coauthor David Greenstein of Vanderbilt University School of Medicine in
Nashville. “This is a mechanism to sense the availability of sperm,” he says.
“This blew our minds because [the sperm] use MSP to crawl around,” says
Greenstein. Sperm of the nematode Caenorhabditis elegans ooze around like amoebas
instead of swimming like, say, human sperm.
Sperm availability is not normally a problem for any particular C. elegans because
each worm has both male and female reproductive organs. But other nematodes have
separate sexes, which means that sperm aren’t always available.
Greenstein suggests that finding agents that interfere with MSP detection by
female tissues, and therefore with fertilization, could lead to drugs for
combating some parasitic intestinal worms in people and domestic animals.