A sperm’s journey isn’t just spent swimming to an egg. Along the way, a sperm acquires tools to complete its mission.
“When the sperm leaves the male tract, it’s not fully mature," said DeLeon. "It’s not able to fertilize an egg. It must some time in the female tract before it gains fertilizing ability.”
Patricia Martin-DeLeon, a reproductive biologist at UD, recently published a study in the Journal of Biological Chemistry about how the Fallopian tube prepares the sperm for fertilization. She and other researchers discovered that the tube releases molecules, which are packed with proteins that help the sperm survive.
One of the proteins lowers calcium levels in sperm. Calcium is important to the sperm’s functioning. However:
“After its activities, the calcium levels must be brought low because the excess calcium is toxic," said DeLeon.
And the sperm needs a way to pump out that calcium or else it becomes sterile.
DeLeon says making sure that sperm have access to this calcium pump and other proteins released in the Fallopian tube can help scientists understand the genes involved in infertility and it can improve success rates of in vitro fertilization.
“If we could replicate that in the lab, we’d probably make a cocktail of proteins that are [from the Fallopian tube], we’d probably get a higher level of fertilization," said DeLeon
Right now the success rate of IVF stands at just 32 percent.
For this study, DeLeon’s laboratory used mice, which are almost genetically identical to humans. But it will be a while before this research can help couples who are struggling to have children. Deleon expects that this research would first be used in agriculture to make IVF more efficient in livestock breeding.
