Sperm defects are often found to be the main cause or a contributing cause of male infertility. Sperm are produced in the testicles through a three-step process called spermatogenesis. During the final stage, known as spermiogenesis, many changes take place, including the packaging of DNA into the sperm head and the formation of the sperm tail, which propels the sperm cell toward the egg.
The research team reported that male mice lacking a protein called meiosis expressed gene 1, or MEIG1, were sterile as a result of impaired spermiogenesis – the process that encompasses changes in the sperm head and the formation of the tail. It was also founded that MEIG1 associates with the Parkin co-regulated gene protein, or PACRG protein, and that testicular PACRG protein is reduced in MEIG1-deficient mice. PACRG is thought to play a key role in assembly of the sperm tail, and the reproductive phenotype of PACRG -deficient mice mirrors that of the MEIG1-mutant mice.
According to Jerome F. Strauss III, M.D., Ph.D., dean in the VCU School of Medicine,“We discovered that MEIG1 is essential for male fertility. Moreover, our findings reveal a critical role for the MEIG1/PACRG partnership in the function of a structure that is unique to sperm, the manchette. The absence of a normal manchette in mice lacking MEIG1 totally disrupts the maturation process of sperm,” said Strauss.
In addition to having found the genetic factor for infertility, the discovery has instilled hopes in the research team that these findings would lead to new approaches to male contraception by helping in discovery of such drug for reversible male method of contraception.
Source: ScienceDaily news release on Possible Genetic Factor For Male Infertility