The Chernobyl nuclear disaster produced genetically mutated dogs

About 350,000 people were evacuated during the 1986 disaster at the Chernobyl nuclear power plant in 1986, leaving their lives and belongings to flee the worst nuclear disaster in history. Left behind but often unmentioned facets of residents’ lives are their pets, which the evacuees were forbidden from returning. Despite the high levels of radiation in the Chernobyl Exclusion Zone, many of these animals survived and their descendants can now be found in and around the region.

Prancer, one of these dogs, gets its name from a dance she performs when she greets Tim Mousseau’s research team. Mousseau, a biology researcher at the University of South Carolina, has been studying the effects of radiation on living organisms at places like Chernobyl and Fukushima for decades. However, his subjects are usually much smaller, possibly due to the extremely harsh conditions created by nuclear radiation.

“Those are dogs. You can’t help but love them and build relationships with them,” he told The Daily Beast. “We always think about taking them home.”

Even under conditions that drastically limit their lifespans — Mousseau said most of the Chernobyl dogs only live to be three years old — the dogs have found a way to thrive. Locals and a growing number of obscure tourists are feeding the dogs, leading to a surge in the dog population that prompts nonprofits and researchers to provide regular veterinary care and spay and neuter as many dogs as possible. Over the course of three years, Mousseau collected hundreds of blood samples from the dogs as part of this effort.

The Blood of the Hounds contained an incredibly rare opportunity: a glimpse into life itself in unnaturally harsh conditions. When Mousseau approached geneticist Elaine Ostrander of the National Human Genome Research Institute to analyze nearly 300 of those blood samples, she didn’t want to pass up the opportunity.

“I said, ‘I, I, I, I, I,'” she told The Daily Beast. “It’s such an extraordinary opportunity and it has implications for human health and biology.”

Mousseau and Ostrander’s team published the results of the genetic sequencing of the Chernobyl dogs in the Journal on March 3 scientific advances. According to the authors, the study “represents the first genetic analysis of domestic dogs affected by a nuclear disaster,” and provides a basis for measuring the effects of prolonged radiation exposure on an animal’s genetic health.

Radiation in the city of Chernobyl and near the power plant is breaking the puppies’ DNA strands. Your cells try to fix it, but errors often occur. DNA is deleted, spontaneously added, or arbitrarily exchanged. Understanding how the Chernobyl dogs are able to survive despite this constant onslaught could inform an area like cancer treatment, since improperly repaired DNA is commonly found in cancer cells, Ostrander said.

“These dogs survive generation after generation, they’re fertile, they perform all their bodily functions, and they even have behavioral relationships with people in the area — they do all the dog stuff they’re supposed to be doing,” Ostrander said. “What allowed them to overcome [the radiation]? From the perspective of someone at the National Institutes of Health, that’s really important to us.”

During visits to the exclusion zone, Mousseau and other dogs have noticed that they live both in Chernobyl city and in and around the nuclear power plant – the latter of which is striking given the area’s high and ongoing radioactive contamination. However, it was unknown how closely related these two populations were and how genetically they were similar to dogs in a nearby village.

As it turned out, both were genetically different – from a nearby village dog population and from each other. The next step, which the researchers are already delving into, is isolating the genetic regions that make the Chernobyl dogs different. For now, this is all speculation, but Mousseau and Ostrandar both have theories.

For his part, Mousseau has studied a range of flora and fauna in radiation zones and found that some bird species have safety mechanisms in their genes that protect them from the worst effects of radiation. Maybe the dogs that live near the power plant have molecular failovers like this too?

Now that the researchers have a baseline for these dogs, they can isolate genetic differences that aren’t just down to the quirks of the populations. Any different finding could improve the dogs’ ability to survive in their environment. For example, if the Chernobyl dogs have genes that code for shorter fur than others nearby, it could mean they don’t retain as much radioactive dust in their fur. Or, if they have more genes related to scent processing, it could mean the dogs can smell without sticking their noses in the radioactive soil.

“In terms of looking at the genome, this is one of the most exciting projects ever,” Ostrander said.

But Russia’s invasion of Ukraine has complicated research efforts. The Crimean Bridge was bombed the last time Mousseau visited the region — his team sends about 800 kilos of food to the dogs every week, and the nonprofit Clean Futures Fund helps care for the animals locally.

“We hope that this research will shed light on the situation in Ukraine to a wider audience,” Mousseau said. “We should all be concerned about the care of animals, even if they are stuck in a war zone in a place like Chernobyl.”