Analysis of the human sperm centrosomal function and the oocyte activation ability in a case of globozoospermia, by ICSI into bovine oocytes

Background: Centrosomal function and oocyte activation ability of human sperm from a case of globozoospermia was assayed by heterologous ICSI into bovine oocytes. Methods: Microtubules and chromatin configuration in bovine oocytes were examined by immunofluorescence after heterologous ICSI with human sperm from two fertile donors and from a globozoospermic man. Results: The microtubule array from the sperm centrosome, the 'sperm aster' and the male pronucleus were observed in bovine oocytes, following ICSI with round-headed sperm from a globozoospermic man. The rate of sperm aster formation and the rate of male pronuclear formation in the bovine oocytes injected with fertile donor sperm were 57.9 and 92.5% respectively; the respective values for oocytes injected with round-headed sperm without artificial oocyte activation were 15.8 and 31.0%. Ethanol activation after ICSI improved male pronuclear formation (84.9%) but not sperm aster formation rate (32.3%) of the globozoospermic patient. Conclusions: These data indicated that sperm from this patient with globozoospermia have centrosomal dysfunction and low ability for oocyte activation compared with fertile donor sperm. The centrosomal dysfunction may be one of the reasons for infertility in this patient.