Chernobyl’s stray dogs are genetically different – but radiation isn’t the cause

In 1986, the Chernobyl nuclear reactor in the Soviet Union, now in Ukraine, explodedspewing large 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 apparently not because of radiation.

Researchers from North Carolina State University (NC State) and Columbia University’s Mailman School of Public Health concluded that genetic differences between dogs from Chernobyl and dogs near the Chernobyl Nuclear Power Plant (NPP) are not driven by radiation-induced mutations. . Their investigation was detailed on December 27 to learn published in the magazine PLoS Oneprovides information on how catastrophic environmental pollution affects nearby populations over time.

“We’re working with two populations of dogs that are genetically distinct, even though they’re only 16 kilometers, or about 10 miles, apart,” said NC State’s Matthew Breen, who participated in the study. statement. “We’re trying to determine whether low-level exposure to environmental toxins such as radiation, lead, etc. over many years may explain some of these differences.” In previous genetic analysesBreen and his colleagues identified almost 400 regions throughout the genome that represent differences between the two dog populations, some of which contain genes associated with DNA damage repair.

In the latest study, the team confirmed that urban dogs are genetically similar to dogs from 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 that might have accumulated in the NPP dogs over time. Germline DNA mutations are, for example, inherited changes in the DNA of reproductive cells. The researchers began their analysis at the chromosome level and then gradually zoomed in on smaller and smaller genetic traits.

“Think of it like using the zoom function on your phone’s camera to get more detail—we start with a wide view of the subject and then zoom in,” Breen explained. “We know that exposure to high doses of radiation, for example, can cause instability from the chromosomal level down. Although this dog population is 30 or more generations removed from the lineage that existed at the time of the 1986 disaster, mutations can still be detected if they gave these original dogs a survival advantage. But we did not find such evidence in these dogs.”

In other words, the researchers did not find genetic mutations that could have been caused by radiation exposure. Evolutionary pressures caused by the nuclear reactor disaster could still have driven the genetic difference between urban dogs and NPP dogs.

“From a human perspective, this would be like studying a population that is centuries removed from the one that existed at the time of the disaster,” said Megan Dillon of NC State, who led the study. “Perhaps dogs that survive long enough to breed already have genetic traits that increase their ability to survive. So maybe there was too much selective pressure to begin with and then the dogs at the power station got separated from the townspeople. Investigating this question is an important next step that we are currently working on.”

Kleiman of Columbia University, who participated in the study, says that the negative effects of the Chernobyl nuclear accident were actually not limited to radiation alone. During the cleanup process, toxins including heavy metals, lead dust, pesticides and asbestos (a carcinogenic mineral) were released into the environment. The broader impact of a 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 overemphasized,” Kleiman said, “given our increasingly technological and industrial societies, there will almost certainly be more such disasters in the future,” and we can better understand the potential health risks and how best to protect people. we must understand.

It is also comforting to know that the puppies roaming near the Chernobyl Nuclear Power Plant have nothing to do with wild dogs. Chernobyl Diaries.