Well One of the worst nuclear accidents in history took place in April 1986. Then the Chernobyl nuclear power plant in Ukraine exploded.
Radioactive dust swirled in the air. This forces the residents of the surrounding area to leave their homes in panic and abandon their pets.
Nearly 40 years later, hundreds of stray dogs roam the Chernobyl Exclusion Zone (CEZ), an area covering about 1,000 square miles around the plant that is restricted due to radioactive and chemical waste from the disaster. As the wild descendants of pets that were abandoned in the fevered aftermath of the Chernobyl disaster, these dogs provide valuable information about the effects of the contaminated environment on mammals, including humans.
Scientists have now found signs that stray dogs from Chernobyl may have adapted to the unusually toxic environment at a basic genetic level – a discovery that could have implications for understanding the risks of exposure to chemicals and radiation on wildlife and humans.
A team led by Megan Dillon, a PhD student at North Carolina State University, analyzed DNA obtained from two populations of Chernobyl dogs: a group that lived in close proximity to the power plant and another that lived near the partially abandoned city of Chernobyl, on about 10 miles from headquarters.
The researchers “found genetic evidence suggesting that these populations may have adapted to the radiation they encountered over many generations,” which could help assess “how the impact of environmental catastrophes such as the Chernobyl nuclear disaster can affect animal populations,” according to the new study, published in Canine Medicine and Genetics.
“Although wildlife in Chernobyl has been the subject of previous ecological and genetic studies, little is known about the population genetics of the more than 500 dogs inhabiting the area around [Чернобилската атомна електроцентрала] and the city of Chernobyl,” Dillon and her colleagues say in the study.
This dog population has grown in the decades since the accident and is believed to consist at least in part of the descendants of pets left behind during the 1986 panic evacuation.”
“In this scenario, it is intriguing to understand to what extent the descendants of these abandoned dogs have adapted to survive and sustain a growing population under these extreme environmental conditions,” the team continues.
“Understanding and expanding the genetic and health consequences of radiological and chemical exposures in these dogs will enhance a broader understanding of how these types of adverse environmental stressors can affect human health.”
The wild dogs of Chernobyl have attracted a lot of public attention and affection in recent years after several documentaries and articles about their lives in the contaminated nature. But they have also become a hot topic for scientists interested in the long-term effects of pollutants on ecosystems and human communities.
To study the genetic characteristics of these animals, Dillon and her colleagues analyzed blood samples taken from a total of 116 unique dogs, which were divided almost equally between the populations from the power plant and from the city of Chernobyl. The samples were obtained in 2018 and 2019 as part of vaccination and sterilization efforts managed by the Chernobyl Dogs project of the Clean Future Fund.
The results revealed that there was very little interbreeding or gene flow between the two populations, despite their geographical proximity. Although both groups are descended from a mixture of different domestic breeds, including the German Shepherd and the West Siberian Laika, they are noticeably genetically different from each other.
What’s more, the team found tantalizing hints that environmental stress at Chernobyl may have led to some unusual genetic changes, particularly in genes that aid in DNA repair, the immune response and other processes that may be linked to exposure. to the impact of exhaust gases from the melting of nuclear material. High levels of radiation at the site are among these environmental stressors, but other factors also include chemicals such as heavy metals, organics, pesticides and other pollutants that have contaminated the CEZ.
More research will be needed to confirm whether these genes do indeed suggest that stray dogs have adapted genetically to their surroundings over the years. To that end, Dillon and her colleagues plan to continue searching for clues to life in the sediments, along with other researchers who have made these dogs the focus of their work.
“As we examine the genomes of dogs at this site, we aim to identify genome variants that have potentially been induced by prevalent exposures over many generations and then subjected to ongoing selective pressure to persist in the population,” Dillon said. and her colleagues in the study. “Our long-term goal with this unique population of dogs is to establish further evidence to assess the extent of local adaptation and thereby develop measures of the impact of the exposures experienced by these dogs.”
“This work, as well as future studies with these dog populations, will contribute to our broader understanding of the genetic effects of chronic exposure to radiation and non-radiation toxicities, and the findings are potentially more broadly applicable to the adverse health effects of other environmental nuclear and non-nuclear catastrophes in both animals and humans,” the team concluded.
