PRESENCE AND LOCALIZATION OF OSCILLIN IN HUMAN SPERMATOZOA IN RELATION TO THE INTEGRITY OF THE SPERM MEMBRANE

We investigated the presence and localization of oscillin in human spe rmatozoa in relation to the integrity of the sperm membrane, which was assessed by the hypo-osmotic swelling (HOS) test, We found no gross d ifferences in the presence of oscillin in semen samples from men who p resented with 70%, 40%, 25% or 2% of membrane-intact spermatozoa, By i mmunofluorescence, membrane-intact (HOS-positive) spermatozoa showed s taining of a single band at the equatorial region, whereas over 80% of HOS-negative spermatozoa consistently showed a diffuse distribution o f oscillin over the sperm head, However, some individuals presented wi th up to 50% of HOS-positive spermatozoa showing an aberrant localizat ion of oscillin, We found a significant correlation rate (r = 0.70, P < 0.05) between the percentage of HOS-positive spermatozoa with an equ atorial oscillin localization and the fertilization rates achieved aft er intracytoplasmic sperm injection, These data suggest that the local ization of oscillin in human spermatozoa might have an impact on egg a ctivation and fertilization rates. (C) 1998 Federation of European Bio chemical Societies.