Impaired ability of human spermatozoa to penetrate zona-free hamster oocytes: is a postacrosomal sheath anomaly involved?
We selected 17 infertile men whose sperm ultrastructural study revealed at least 70% of spermatozoa with postacrosomal sheath (PAS) anomalies. Among the other sperm head defects, those affecting the nuclear shape were most frequently encountered and were highly correlated with PAS anomalies (r = +0.71; P less than .01). PAS anomalies were also correlated with chromatin condensation defects (r = +0.67; P less than .01) and acrosome anomalies (r = +0.53; P less than .05). Those spermatozoa were tested for their ability to penetrate zona-free hamster oocytes and were compared to a control sperm population. It was shown that sperm head morphological anomalies impaired the ability of spermatozoa to attach to and penetrate the oocyte. The highest significant and negative correlations were found between the penetration rate and 1) the percentage of spermatozoa with PAS anomalies (r = -0.81; P less than .01) and 2) the percentage of spermatozoa with nuclear shape anomalies (r = -0.66; P less than .01). The effect of PAS anomalies on human fertilization process are discussed.
D000177:Acrosome / Q000502:physiology*; D000818:Animals; D006224:Cricetinae; D005260:Female; D006801:Humans; D007248:Infertility, Male / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009865:Oocytes / Q000502:physiology*; D010063:Ovum / Q000502:physiology*; D013077:Sperm Head / Q000648:ultrastructure; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000002:abnormalities* / Q000502:physiology*; D015044:Zona Pellucida / Q000502:physiology*