News Worm sperm stimulate ovulation By Jessa Netting April 25, 2001 at 12:14 pm - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Share on Facebook (Opens in new window) Facebook Share on Reddit (Opens in new window) Reddit Share on X (Opens in new window) X Print (Opens in new window) Print 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.