Science / Medicine : Sperm Cell Catalyst May Help in Treating Infertility

A new clue to how mammalian eggs attract sperm may lead to new treatments for infertility. Follicle cells in the reproductive tract, and presumably the eggs themselves, emit a chemical that causes sperm to migrate toward the egg, researchers from the Weizmann Institute of Science in Rehovot, Israel, report in today’s edition of the Proceedings of the National Academy of Sciences.

It has been known that a large fraction of the sperm entering the female reproductive tract remains motionless in storage sites until ovulation occurs, at which time the sperm movement resumes, enabling them to reach the fertilization site in the Fallopian tube within minutes. It was not known, however, what triggers this burst of movement.

A team headed by Weizmann biophysicist Michael Eisenbach extracted follicular fluids from women undergoing in vitro fertilization procedures and found that these fluids, in the test tube, attract sperm. In contrast, fluid from follicles that are not nurturing an egg capable of being fertilized do not attract sperm.

The researchers are now attempting to identify the chemical attractant in hopes that it may be used to stimulate conception in some infertile couples.