Most marine mammals are missing a mysterious gene

In the News

Most marine mammals are missing a mysterious gene

August 15, 2018

A gene that protects land-dwelling mammals from certain pesticides lost its function during adaptation to life in the sea.  

During their evolution from land to sea, the genomes of marine mammals lost the function of a number of genes common in terrestrial animals.  Genes for smell and taste, for example, unsuprisingly underwent many changes. 

In a compartive genome study in a recent edition of Science, the reseachers did not expect to find that marine mammals, like whales, manatees and seals, no longer have the function of an important ancient gene.  This gene, called PON1, codes for a protein that helps modern-day terrestrial animals clear certain pesticide toxins from their bodies. 

National Geographic reporter Nadia Drake examined this research and its implications. The scientsts are recommending monitoring waterways and marine mammal habitats to determine if agricultural run-off of organophosphate pesticides might be affecting these species of mammals.  Among the researchers on the study interviewed for her article was Clement Furlong, a professor of medicine in the Division of Medical Genetics and a professor of genome science.

Furlong had previoulsy conducted decades-worth of studies on mice and human genetic susceptibility and resistance to the neurotoxic effects of organophosphates, particularly chlorpyrifos. That subtance is now banned from residential use.

Furlong told National Geographic, “All of the data that we have in the mouse model and with humans indicate that PON1 is crucial for determining your resistance for exposure. The data backing that up are very strong.” Furlong also mentioned that the young  are particularly vulnerable to the nerve and brain effects of thees pesticides, because their bodies don't yet manufacture enough of the  PON1 protein. 

The newly reported research project was headed by Nathan Clark, an evolutionary biologist at the University of Pittsburgh.