1986 Chernobyl nuclear reactor in the Soviet Union, now in Ukraine, explodedreleasing huge amounts of radioactive material into the environment. Nearly four decades later, the 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 Mailman School of Public Health concluded that genetic differences between dogs in the city of Chernobyl and dogs near the Chernobyl Nuclear Power Plant (NPP) are likely not caused by radiation-induced mutations. Their research, detailed in December 27 study published in the journal PLOS Oneprovides insight into how catastrophic environmental contamination affects nearby populations over time.
“We were working with two populations of dogs that are genetically distinct, even though they are separated by only 16 kilometers, or about 10 miles,” 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.” IN previous genetic analysesBreen and his colleagues identified nearly 400 regions along the genome that represent differences between the two dog populations, some of which contain genes associated with DNA damage repair.
In a recent study, the team confirmed that the city’s dogs are genetically similar to dogs in nearby regions such as Russia and Poland, which set them up 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 heritable changes within the DNA of reproductive cells. The researchers began their analysis at the chromosomal level, then progressively approached smaller and smaller genetic features.
“Think of it as 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, for example, exposure to high doses of radiation can introduce instability from the chromosomal level down. Although this population of dogs 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 on 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 pressures caused by the nuclear reactor disaster may still have affected the genetic difference between the city dogs and the dogs from the NPP.
“In human terms, this would be like studying a population that is centuries removed from the one that was present at the time of the disaster,” said Megan Dillon of NC State, who led the study. “It is possible that dogs that survived long enough to breed already had genetic traits that increased their ability to survive. So there may have been extreme selective pressure in the beginning, and then the dogs at the power plant simply remained separated from the urban population. Researching that question is an important next step that we are working on now.”
The harmful effects of the Chernobyl nuclear accident were actually not limited to radiation, said Columbia University’s Kleiman, who was also involved 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 wider impact of a nuclear disaster on nearby dog populations provides important clues about how future contamination crises might 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, “because it is certain, given our increasingly technological and industrial societies, that there will always 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 cubs roaming near the Chernobyl nuclear power plant have nothing to do with the wild dogs of Chernobyl diaries.