On April 26, 1986, the greatest nuclear disaster in history occurred in Chernobyl in Ukraine, some three kilometers from the city of Pripyat. The consequences of the explosion of reactors 4 and 5 of the plant were catastrophic with more than 200,000 people evacuated, hundreds of radiation-related deaths and nature changed forever.
The affected area, which covers an area of 2,600 km², suffered significant damage to the fauna and flora, but nature has since regained its rights there. In this regard, the mini-series Chernobyl written by Craig Mazin offers a fluid narration of the unfolding of events, from the beginning of the disaster until today.
A unique genomic signature
As our colleagues from Science and Futurethe effects of radiation have only been studied in mice “but no genetic study on large mammals had ever been conducted”.
In 2017, a team of American researchers took around 300 blood samples from stray dogs in three specific areas: one near the plant, another 15 kilometers away, in the city of Chernobyl, and the third 45 kilometers away, in the village of Slavutych.
Published during the month of March (ici), the results of this survey show that the cases closest to the plant have a level of cesium-137, a toxic radioelement, two hundred times higher than those who live in the nearby town of Chernobyl.
Moreover, the populations of stray dogs studied are genetically different from each other. “Genetic differentiation from other free-roaming purebred dogs suggests that Chernobyl populations have a unique genomic signature,” the experts decipher in their report.
How did they survive?
From these initial findings, scientists want to go further and understand how dogs managed to adapt to survive in one of the most radioactive places in the world. The challenge of these analyzes is then to understand the effects of long-term exposure to radiation on genetics and human health.
David Brenner, a bio-physicist at Columbia University who conducted this study and quoted by the magazine Georecognizes that it will be complicated, however, to determine the genetic changes that have been caused by radiation from those resulting from other factors.
Christophe Hitte, from the Dog Genetics team (IGDR, Rennes), relayed by our colleagues from Sciences et Avenir, believes “that the genes involved in the repair of their DNA should be more effective in a hostile situation than in an average dog who does not ‘will not have survived’. The scientist is, however, very enthusiastic: “A colony of relatively isolated dogs that have reproduced for 30 years in such a mutagenic environment is material of choice for a geneticist!”.
