“We have previously isolated and characterized BSPs from many species, such as bulls and boars,” says Puttaswamy Manjunath, senior author and a professor in the departments of medicine and of biochemistry at the Universite de Montreal and a member of the Maisonneuve-Rosemont Hospital Research Center.
“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.”
Manjunath and his team sought to isolate human BSP for over 10 years. But, because of the unusual location and the extremely tiny amounts in which it’s produced, they were unsuccessful. Finally, they turned to genetic engineering. Knowing which gene codes for BSP, they cloned it. This allowed them to produce BSP in quantity and purify it.
“After considerable troubleshooting, we were able to produce functional human BSP. Our next steps are to confirm its biological role in human fertility,” Manjunath said.
In other animals, such as cows, sheep, pigs and other hoofed animals, BSPs work by helping the sperm, once they have entered the female reproductive tract, to change, mature and adapt to the new female environment so they can seek out the ova. The sperm experience, for example, a redistribution of surface proteins, a loss of sperm membrane fats and increased movement.