Sperm centrosome dysfunction: a possible new class of male factor infertility in the human.

This study examined the normality of microtubule growth and aster development from the sperm centrosome in failed fertilizations and pronuclear-arrested eggs after intracytoplasmic insemination with spermatozoa derived from severe oligoteratozoospermic individuals. In these cases, male factor was of unknown origin or was associated with vasectomy reversal in men with known prior fertility. The findings indicate that an impaired capacity to promote the growth of microtubule arrays from the sperm centrosome may preclude pronuclear opposition required for syngamy. Centrosome dysfunction may contribute to the developmental arrest of human embryos at the pronucleate stage and consequently may represent a new class of sperm defects associated with early human developmental failure.