Genetic differences in Chernobyl dogs are not due to radiation

Jan. 13 () –

It is unlikely that the radiation induced mutation has caused genetic differences between the dog populations of the city of Chernobyl and the nearby Chernobyl nuclear power plant.

It is the conclusion of a new study, published in PLOS ONEwhich has implications for understanding the effects of environmental pollution on populations over time.

“We have been working with two populations of dogs that, although separated by only 16 kilometers, or about 10 miles, are genetically distinct,” he says. in a statement Matthew Breen, Oscar J. Fletcher Distinguished Professor of Comparative Oncologic Genetics at North Carolina State University. “We’re trying to determine whether low-level exposure over many years to environmental toxins like radiation, lead, etc., could explain some of those differences.” Breen is the corresponding author of the study.

Previously, the team had analyzed genetic variants distributed throughout the genome and identified 391 atypical regions in the dogs’ DNA that differed between the two populations. Some of these regions contained genes specifically associated with DNA damage repair. In this new study, researchers took a deeper dive into the dogs’ genomes to detect evidence of mutations that may have accumulated over time.

“First, we contextualized the level of genetic differences between two populations of dogs, which indicated that “The genetics of the Chernobyl city dogs were very similar to the dog populations of Russia, Poland and surrounding areas,” says Megan Dillon, a doctoral candidate at NC State and lead author of the study. “That way, we were able to use the dogs from the city of Chernobyl as a representative control population to compare with the dogs from the Chernobyl nuclear power plant.”

Researchers began looking for differences first at the chromosomal level, then in small intervals of the genome, and then differences in individual nucleotides. The team looked for abnormalities and evidence of accumulated mutations in germline DNAchanges that occur in the DNA of reproductive cells and are passed from parents to children over time.

NO EVIDENCE MORE THAN 30 GENERATIONS SINCE THE ACCIDENT

“Think of it like using the zoom feature on your phone’s camera to get more details: We start with a wide view of a subject and then zoom in,” Breen says. “We know that, for example, exposure to high doses of radiation can introduce instability from the chromosomal level down. Although this dog population is 30 or more generations removed from the 1986 disaster, It is likely that the mutations would still be detectable if they conferred a survival advantage to the original dogs, but we found no evidence of it in these dogs.”

Although no evidence of genetic mutation was found, the researchers add that That does not rule out the role of selective pressures in explaining the differences between the two dog populations.

“In human terms, this would be like studying a population that is centuries away from what it was at the time of the disaster,” Dillon says. “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 at the beginningand then the power plant dogs were simply kept separate from the city’s population. Investigating that question is an important next step that we are working on now.”

The researchers note that these findings are only part of a larger picture about the role that adverse environmental exposures can play in canine (and human) health.

“Most people think of the Chernobyl nuclear accident as a radiological disaster in an abandoned corner of Ukraine, but the potential adverse health implications are much broader,” says Norman Kleiman, co-author and professor of environmental health sciences at Columbia University School of Public Health. “This is due to the many other toxins, including heavy metals, lead dust, pesticides and asbestos, released into the environment during subsequent cleanup and remediation efforts over three decades.

“While no one lives at the nuclear power plant or in Pripyat anymore, until the Russian invasion, many thousands of people were still working there every day on nearby remediation and construction projects,” says Kleiman. “Studying pets like these dogs “provides a window into the types of adverse health risks that people may face.”

In addition to studying the dogs’ genetics, the team also recently identified differences in ticks recovered from dogs at the power plant and in the city of Chernobyl, and the prevalence of the pathogens they transmit. These results, published in the journal Parasites and Vectors, may reflect differential exposures to both ticks and microbes in the two locations.