Egg cells send out chemical signals to entice sperm

BioNews - Egg cells send out chemical signals to entice sperm, suggests study: Progesterone released from an egg may help guide sperm towards it and assist sperm to penetrate the egg's protective layers, according two studies published in Nature. The discovery could potentially help in the development of non-hormonal contraceptives for men and women, while also explaining some cases of infertility.