Growth characteristics of two HeLa S3 strains possessing low level glucocorticoid-inducible and high level suppressible alkaline phosphatase.

Sperm of the sea urchin, Anthocidaris crassispina loses its fertilizing capacity, without losing its motility, on prior exposure to both native and trypsin-digested, univalent Concanavalin A (Con A). Neither agglutination nor acrosome reaction is evoked by ConA treatment. Fluorescein-conjugated ConA binds to the apex of sperm head and to the midpiece. The observed effects of ConA are cancelled by methyl α-d-mannoside. ConA neither binds to sperm of Hemicentrotus pulcherrimus nor renders it infertile. Fertilizability of egg of both species is not reduced by ConA, though formation of the fertilization membrane and 1st cleavage are seriously affected. It is suggested that the species-specific polysaccharide component is situated on the apex of the sea urchin sperm head and constitutes the counterpart to the sperm-binding protein of the vitelline membrane of the egg which belongs to the same species.