Stray dogs in Chernobyl are genetically different, but radiation is not the cause

In 1986 the Chernobyl nuclear reactor in the Soviet Union, now in Ukraine, explodedreleasing huge amounts of radioactive material into the environment. Almost four decades later, stray dogs roaming near the Chernobyl nuclear power plant are genetically different from those in the nearby city of Chernobyl, but that’s probably not because of the radiation.

Researchers from North Carolina State University (NC State) and Columbia University’s Mailman School of Public Health have concluded that the genetic differences between dogs in the city of Chernobyl and those near the Chernobyl nuclear power plant (NPP) are probably not due to mutations. induced by radiation. Their research, detailed on December 27 study published in the journal PLoS Oneprovides insight into how catastrophic environmental pollution affects nearby populations over time.

“We’re working with two populations of dogs that, although separated by only 16 kilometers, or about 10 miles, are genetically distinct,” said Matthew Breen of NC State, who participated in the study at the University statement. “We are trying to determine whether low-level exposure over many years to environmental toxins such as radiation, lead, etc., can explain some of these differences.” previous genetic analysesBreen and his colleagues have identified nearly 400 regions along the length of the genome that represent the differences between the two dog populations, some containing genes related to DNA damage repair.

In the recent study, the team confirmed that urban dogs are genetically similar to dogs in nearby regions such as Russia and Poland, establishing them as a representative control population against which to compare the NPP group. They then looked for abnormalities and mutations in the NPP dogs that could have accumulated over time. Germline DNA mutations, for example, are inherited changes in the DNA of reproductive cells. The researchers began their analysis at the chromosomal level and then progressively zoomed out to smaller and smaller genetic features.

“Think of it as using the zoom feature on your phone’s camera to get more detail—we start with a wide view of an object and then zoom in,” Breen explained. “We know that, for example, exposure to high doses of radiation can lead to instability from the chromosomal level down. Although this dog population is 30 or more generations removed from that present during the 1986 disaster, the mutations would likely still be detectable if they conferred a survival advantage to these original dogs. But we found no such evidence in these dogs.

In other words, the researchers found no genetic mutations that could be caused by radiation exposure. However, the evolutionary pressure caused by the nuclear reactor disaster may still have been responsible for the genetic difference between city dogs and nuclear power plant dogs.

“From a human perspective, it would be like studying a population that is centuries removed from what was present at the time of the disaster,” said Megan Dillon of North Carolina State, who led the study. “It’s possible that dogs that survived long enough to breed already had genetic traits that increased their ability to survive. So maybe there was extreme selective pressure in the beginning and then the dogs at the power station just got separated from the urban population. Investigating this question is an important next step that we are now working on.

The adverse effects of the Chernobyl nuclear accident are actually not limited to radiation, said Kleiman of Columbia University, who also participated in the study. Toxins including heavy metals, lead dust, pesticides and asbestos (a carcinogenic mineral) were released into the environment during the cleanup process. The broader impact of the nuclear disaster on nearby dog ​​populations provides important clues about how future pollution crises may affect human health.

“The importance of continuing to study the environmental health aspects of large-scale disasters such as this cannot be overstated,” Kleiman said, “as it is certain, given our increasingly technological and industrialized societies, that there will inevitably be other such disasters in the future and we need to understand the potential health risks and how best to protect people.

It’s also a relief to know that the pups roaming near the Chernobyl nuclear power plant have nothing to do with the wild dogs of Chernobyl diaries.