Penetration of mouse eggs in vitro: optimal sperm concentration and minimal number of spermatozoa.
D000818:Animals; D002452:Cell Count; D005260:Female; D005306:Fertilization; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D010063:Ovum / Q000502:physiology; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000502:physiology