The molecular basis of sea urchin gamete interactions at the egg plasma membrane.

Fertilization is the result of a series of well-choreographed interactions between molecules located on the surfaces of the egg and the sperm. The recent molecular characterizations of several of these surface molecules has led to a greater understanding of their roles in gamete recognition and binding. We present a review of these recent advances with emphasis on the sea urchin, a classic system for the study of fertilization. In particular, the structure and function of the sea urchin egg plasma membrane receptor for sperm, a novel cell recognition molecule, is discussed.