A Specialized Role for the Pacific Herring Egg Chorion in Sperm Motility Initiation

The micropyle region of the eggs of Pacific herring (Clupea pallasi) has been shown to play an active role in the activation of herring sperm (Yanagimachi and Kanoh, 1953; Yanagimachi, 1957; Yanagimachi et al., 1992; Pillai, et al., 1993; Griffin et al., 1996. Unlike the sperm of most organisms, herring sperm are virtually immotile at the time of spawning, however, contact with the micropyle region of the herring egg initiates sperm motility. Our laboratory has focused on the basic mechanisms of the above phenomenon during herring gamete interaction, as well as the role of environmental factors in modulating fertilization.