Motility, expression of surface antigen, and X and Y human sperm separation in in vitro fertilization medium

The influence of surrounding medium on human sperm swimming behavior has been characterized. In modified Ham's F-10 serum-supplemented in vitro fertilization medium, the straight-track swimming pattern of sperm in semen changed rapidly into circular tracks, and a new surface antigen was detected soon after this change. The circular tracks alternated between clockwise and counterclockwise directional movements. Addition of 17 beta-estradiol in a concentration range found in follicular fluid increased the frequency of clockwise movement twofold, suggesting that a steep concentration gradient created by an aduterine flow during ovulation, is likely to direct sperm migration up the gradient in the ipsilateral oviduct. Separation of X and Y sperm raised the possibility that a female carrier of an X-linked disease might choose to have a daughter, instead of taking the chance of having an affected son.