PITTSBURGH, Aug. 9, 2018 – As marine mammals evolved to make water their primary habitat, they lost the ability to make a protein that defends humans and other land-dwelling mammals from the neurotoxic effects of a popular man-made pesticide, according to new research from the University of Pittsburgh School of Medicine.
The implications of this discovery, announced today in Science, led researchers to call for monitoring our waterways to learn more about the impact of pesticides and agricultural run-off on marine mammals, such as dolphins, manatees, seals and whales. The research also may shed further light on the function of the gene encoding this protein in humans.
“We need to determine if marine mammals are, indeed, at an elevated risk of serious neurological damage from these pesticides because they biologically lack the ability to break them down, or if they’ve somehow adapted to avoid such damage in an as-yet undiscovered way,” said senior author Nathan L. Clark, Ph.D., associate professor in Pitt’s Department of Computational and Systems Biology, and the Pittsburgh Center for Evolutionary Biology and Medicine. “Either way, this is the kind of serendipitous finding that results from curiosity-driven scientific research. It is helping us to understand what our genes are doing and the impact the environment can have on them.”
Clark and lead author Wynn K. Meyer, Ph.D., a postdoctoral associate in his laboratory, knew from previous research by other scientists that some genes behind smelling and tasting lost their function during the evolution of marine mammals. They set out to see what other genes conserved in land-dwelling mammals had lost function in marine mammals.
By analyzing DNA sequences from five species of marine mammals and 53 species of terrestrial mammals, the team found that Paraoxonase 1 (PON1), was the gene that best matched the pattern of losing function in marine mammals while retaining function in all terrestrial mammals. …