Pig Sperm's Secret: How a Hormone Shapes Its Journey

Ever wondered what helps pig sperm swim and look their best? A hormone called GnRH-II and its receptor, GnRHR-II, might hold the key. These guys are super abundant in a pig's testes, hinting they play a big role. Scientists found that GnRHR-II is way more common in the testes than other reproductive parts. It's like the receptor's favorite hangout spot! In the testes, GnRHR-II loves to hang around elongating spermatids, the intermediate stage of sperm development. Even in ejaculated sperm, it's found in the connecting piece, the tiny bridge between the sperm's head and tail.But how does this hormone duo affect sperm? Researchers treated pig semen with GnRHR-II agonists and antagonists to find out. They discovered that a GnRHR-II agonist, D-ala6 GnRH-II, might reduce the number of sperm with bent tails. On the flip side, an antagonist, SB-75, seemed to mess up semen metrics at high concentrations. Interestingly, combining both substances partially improved sperm motility and shape. This suggests that GnRH-II and its receptor might be communicating with sperm in a local, back-and-forth manner, helping them function better.