Influence of the male reproductive tract on the reproductive potential of round spermatids abnormally released from the seminiferous epithelium

Round spermatids can be collected from testicular biopsy material or occasi onally from semen samples. We evaluated the influence of the passage of rou nd spermatids through the male reproductive tract on their reproductive pot ential. A model of abnormal release of round spermatids from the seminifero us epithelium was created in mature male rats (group A). Additional sham-tr eated rats of the same age served as a control group (group B). Round sperm atids were collected from the testicles of rats of both groups, the epididy mides of rats of group A, and the vaginae of mature female rats mated with rats of group A. Isolated round spermatids were processed for ooplasmic inj ections. Injected oocytes were cultured. At 96 h post-injection, the blasto cyst development rate was significantly higher in the groups of oocytes inj ected with testicular spermatids than the groups of oocytes injected with s permatids recovered from the vaginae, or the head, body, or tail of the epi didymides, It appears that round spermatids recovered from testicular biops y material have larger reproductive capacity than ejaculated round spermati ds, due to mechanical or chemical detrimental influences of storage/passage through the male reproductive tract (outside the testicle) on the capacity of round spermatids to induce optimal early embryonic development.