Abstract
Among a wide diversity of sexually reproducing species, male ejaculates coagulate to form what has been termed a copulatory plug. A number of functions have been attributed to copulatory plugs, including, but not limited to, the inhibition of female remating and the promotion of ejaculate movement. Here we demonstrate that copulatory plugs also influence the likelihood of implantation, which occurs roughly four days after copulation in mice. Using a bead transfer method to control for differences in ejaculate retention and fertilization rates, we show that implantation rates significantly drop among females mated to genetically engineered males incapable of forming plugs (because they lack functional TGM4, the main enzyme responsible for its formation). Surprisingly, this result does not correlate with differences in circulating progesterone levels among females, an important hormone involved in implantation. In this paper we discuss three models that connect male-derived copulatory plugs to implantation success, including the hypothesis that plugs contribute to a threshold amount of stimulation required for females to become receptive to implantation.
AFTER MORPHOLOGY PRIORITIZATION PGT-A SHOULD IMPROVE IMPLANTATION RATES BY 10%
