Tech & Appsbreaking news
Chernobyl's dogs are genetically closer to Galapagos dogs than to dogs 16 km away
A genome study of 106 dogs finds signs of natural selection at the Chernobyl power plant, in regions tied to DNA repair and immunity.
A genetic profile of their own
Dogs in Chernobyl city are more genetically similar to dogs in the Galapagos Islands than to the dog population at the nuclear plant, according to Megan Dillon [1]. The dogs living near the Chernobyl Nuclear Power Plant disaster site have a unique genetic profile and are not like other dogs, at least in their genomes [1].
Dillon is a postdoctoral researcher at North Carolina State University and first author of the study [1]. Matthew Breen, a professor of genomics at the same university, is the study's senior author [1].
How the comparison worked
The new research analyzed whole-genome sequence data from 106 dogs collected between 2018 and 2019 [2]. The researchers compared DNA from dogs living right around the nuclear plant with DNA from dogs in the city of Chernobyl, about 16 kilometers away [1].
The comparison showed that random chance alone could not explain the differences between the two populations [1]. The dogs at the nuclear site appear to have been experiencing natural selection [1].
What the genomes show
The researchers found changes concentrated in genomic regions near genes associated with cancer, cellular function and maintenance, infectious diseases, and immune response [2]. Some of the regions under the highest selective pressure were associated with functions such as DNA repair, immunity, and cell survival [1].
The variants likely already existed among local dogs and became more common over the past 40 years, rather than being new mutations [1]. Dillon suggested the founding population at the power plant may have had a genetic toolkit that allowed it to endure and survive harsh conditions [1].
How the dogs got there
The Chernobyl plant had a catastrophic explosion on 26 April 1986, after which Soviet authorities abandoned the area and declared an exclusion zone of about 2,600 square kilometers (1,000 square miles) [2]. Many residents were forced to leave their pets behind, and 'liquidators' were sent in to destroy the remaining animals and livestock in the contaminated area [2].
Chernobyl's dogs are descended from pets left behind during the evacuations [1]. Several hundred dogs are now estimated to inhabit the exclusion zone [2]. They have persisted through Ukraine's harsh winters and have been exposed to other pollutants, including heavy metals and pesticides, deposited in the area [1].
What came before
A 2023 study found that dogs living near the abandoned plant were genetically distinct from dogs living further away, which left open the possibility that mutations from lingering radiation caused the differences [2]. A 2024 follow-up study found no evidence that mutations were driving the genetic differentiation between the dog groups [2].
Other animals have returned to the zone. Wolves, deer, wild boars, and lynx now roam the exclusion zone, a return researchers largely attribute to the decline in human activity [1]. Researchers have observed genomic distinctions in the wolf population similar to those seen in the dogs [1].
What the researchers cannot say
Dillon said the genomic signatures are suggestive of selection, though it cannot be said for certain that they can be directly confirmed as selection [2]. She also said the researchers cannot yet say that the selection evidence is tied to the exposures the dogs have faced, and the environmental factors that favored these variants remain unclear [1].
Breen said the first few years after the disaster were probably the most critical period, when any selection would have occurred [1]. Obtaining samples from the dogs who lived there in 1986 is not possible [1]. The researchers also do not have longitudinal samples that would show exactly how the dog population has changed over time [1].
What this means for you
If you follow the Chernobyl story, the main finding is that the dogs at the plant differ genetically from dogs in Chernobyl city, and chance alone does not explain it [1]. Treat the cause as open, because the researchers cannot yet tie the selection evidence to the exposures the dogs have faced [1].
Earlier work is a reminder to read each result in context. The 2023 study left radiation-caused mutations open as an explanation, and the 2024 follow-up found no evidence that mutations drove the differences [2].
Sources
Written from the sources above and checked twice before publishing. How we work · Report an error
.jpg){kind=link}