Author: Cassie Martin / Source: Science News for Students
Creatures deal with toxic chemicals in their environments in many ways. One strategy: Destroy them with chemical-busting proteins.
Many mammals have a gene that helps them break down certain toxic chemicals. But sea-dwelling mammals have a dud version of this gene, new research shows. And without it, manatees, dolphins and other marine mammals appear vulnerable to dangerous pesticides.The gene is called PON1. It carries instructions for making a protein that interacts with fatty molecules in the blood. But that protein has taken on another role in recent decades. It helps break down harmful chemicals found in a class of common pesticides. These chemicals are called organophosphates (Ohr-GAN-oh-FOSS-faytz). Farmers spray them onto many crops to fend off hungry insects.
But those chemicals don’t always stay put, notes Wynn Meyer. She studies evolution and genetics at the University of Pittsburgh in Pennsylvania. Rains wash these pesticides off of farm fields and into rivers and streams, she says. From there, they can pollute waterways and coastal areas.
That risks poisoning wildlife. But PON1 may offer a defense. It might help break down chemicals that get into animals’ bodies. Meyer and her colleagues wanted to know whether differences in the PON1 gene affected how animals dealt with pesticides.
First, they looked at the genes of 53 species of land mammals.
All had a working form of PON1. And in lab tests, blood from five of the species — including sheep, goats and mice — could break down two pesticides. When mixed with blood from one of these species, the amount of the toxic chemicals dropped over time. Something in the blood — possibly PON1 proteins — was breaking them down.The same was not true for aquatic mammals….
The post A ‘ghost’ gene leaves sea mammals vulnerable to some toxic chemicals appeared first on FeedBox.