The role of ventral prostate in reproduction: A study in the mouse

Removal of paternal ventral prostate gland has previously been shown to deregulate fertility in mice. It is hypothesized that secretions of ventral prostate gland might act on the sperm during its passage in the female genital tract and reduce fertility by adversely affecting embryonic development. To test our hypothesis, sexually mature male mice were subjected to bilateral surgical removal of ventral prostate gland (VPX). Sham operated animals (SH) served as controls. Female mice mated with VPX or SH males were sacrificed at appropriate time to recover uterine spermatozoa, 1-cell stage embryos, pre- and post-implantation embryos. Effects of ablation of ventral prostate gland on fertilization ability in vivo and in vitro, egg activation and pre- and post-implantation embryo development were investigated.; First, the number of oocytes inseminated by sperm from VPX males in vivo and in vitro compared well with that of control males. Thus the fertilization ability of sperm was not affected in the absence of paternal ventral prostate. Secondly, formation of pronuclei and DNA synthesis at 1-cell stage were delayed in the VPX group, accumulation of the nuclear factor-κB/p65 in pronuclei was deregulated, indicating that egg activation was adversely affected. Thirdly, compared with the control, significantly high number of VPX embryos died during postimplantation period. Structural integrity of conceptus that survived was not affected. In addition, there was an effect on differentiation during somitogenesis as a higher number of somites was found in VPX group compared to control group. This part of the study showed that deletion of ventral prostate gland in male mouse led to abnormal development of the sired embryos. These effects could be detected soon after gamete fusion and appeared to affect every stage of development from preimplantation through postimplantation to the late gestation period.; In addition, reduced fertility may also be due to higher incidence of infertile mating upon ablation of ventral prostate glands. This was positively correlated with defective sperm transport to oviducts in the female and was probably due to decrease in the size of copulatory plug, number of sperm and volume of uterine horn content.; Taken together, the outcome of research work described in this thesis confirms a role for the mammalian ventral prostate gland in maximizing reproductive performance by ensuring proper transport of sperm to the site of fertilization and proper development of the embryos.