Time relations of squirrel monkey (Saimiri sciureus) sperm capacitation and ovum maturation in an in-vitro fertilization system.

First polar body expulsion in the squirrel monkey ovum occurred at an average of 13.1 h after hCG injection when observed in culture but could occur as early as 5 h after hCG. the mean time for extrusion of the second polar body was 4.7 h after insemination of the culture with freshly ejaculated spermatozoa (16.3 h after hCG). The earliest time, and therefore also that of sperm capacitation, was 2 h after insemination. First cleavage occurred 16.2 h after insemination.