Human Sperm-Oocyte Fusion

Abstract

Sperm-oocyte fusion is the key event of fertilization in the human, as well as in animals. It is a classic example of spontaneous membrane fusion between 2 cells without the intervention of agents such as viruses or chemicals. The process of gamete fusion has been extensively studied in various animals, including mammals (see reviews, Yanagimachi, 1981, 1988a,b; Bedford, 1983; Monroy, 1985; Longo, 1989), but there is little information about gamete fusion in the human (Soupart, 1980; Sathananthan and Chen, 1986; Sathananthan et al, 1986a, 1987). Yanagimachi (1988a,b) has comprehensively reviewed sperm-egg fusion in animals. This chapter will concentrate on what is known in the human with reference to recent reviews of gamete membrane fusion in mammals. The recent impact of IVF and new technologies of assisted reproduction such as microinsemination sperm transfer (MIST) beneath the zona, using a micromanipulator (Ng et al, 1988, 1989a) have further helped us understand the events that lead up to gamete fusion and microfertilization (Trounson, 1987; Laws-King et al, 1987; Sathananthan et al, 1989).