Scientists may have reached a step closer to realizing novel treatments for infertility, for they have for the first time cloned important sperm-binding proteins.
The researchers at the University of Montreal and Maisonneuve-Rosemont Hospital Research Center say that their success in producing and purifying a protein key to sperm maturation, termed Binder of Sperm (BSP), may have implications for both fertility treatments and new methods of male contraception.
"We have previously isolated and characterized BSPs from many species, such as bulls and boars," says Dr. Puttaswamy Manjunath, senior author and a professor in the departments of medicine and of biochemistry at the University of Montreal and a member of the Maisonneuve-Rosemont Hospital Research Centre.
"We know from these studies that if this protein is missing or defective in these species, fertility is compromised. We believe that BSP is equally important in humans," the researcher added.
In most mammals, BSPs are typically produced by the seminal vesicles and added to sperm at ejaculation. Yet this is not the case for humans, primates and rodents.
Dr.Manjunath says that these species produce small amounts of BSPs only in the epididymis, a duct that connects the testes to the urethra.
"For a few years, we were looking in the wrong place. In addition, the minute quantities of BSP produced in humans has made it impossible to isolate and characterize," says Dr. Manjunath.
He and his colleagues used molecular biology technique to clone the gene (DNA) that encodes human BSP, which enabled them to produce and purify this protein.
"After considerable troubleshooting, we were able to produce functional human BSP. Our next steps are to confirm its biological role in human fertility," says Dr. Manjunath.
A research article on the breakthrough work has been published in the journal Molecular Human Reproduction.