The strange genome decoding of dogs in Chernobyl

On April 26, 1986, the worst nuclear disaster in the world occurred at Chernobyl nuclear power plant in northern Ukraine today. After one of the reactors of the factory exploded in the test, it spit out high energy radioactive radioactive, polluting about 150,219 km2 of land in Belarus, Russia and Ukraine. Shortly after, in order to reduce the spread of radioactive elements from the accident, the hygiene staff was tasked with handling thousands of radioactive animals around the factory, including the ornamental dog left in the beginning. canopy. Nowadays, in Chernobyl, the remaining radioactive amount in the area from the lower level is thousands of times higher than the natural radioactive radiation.

Scientists still argue with radioactive exposure for a long time whether it affects whether the genome of their living and young animals in the Chernobyl area around the factory. Finally, it is difficult to determine the relationship between radioactive exposure and change in various organizations. Different from strict conditions in the laboratory, the actual environment in the prohibited area is from a 30 km radius around the factory with all kinds of complex elements. “It is really a mixture of toxic carcinogens, any of them or their combination can lead to changes we are seeing,” said Matthew Breen, geneticist At the University of North Carolina, said.

The freelance breeding dogs wandering in the forbidden area may be descendants of the abandoned pets, helping to provide some clues about radioactive exposure and genetic change. In a 2023 study, scientists showed that dogs living in a genetic difference in the surrounding dog population. But according to the new research published in December 2024, those differences are most likely not the results from radioactive as many experts doubt.

If the dog in Chernobyl does not undergo rapid evolution due to the direct influence of radiation, what causes that phenomenon? The type of genetic research in this disaster area does not focus on large mammals like dogs until recently. Currently, researchers like Breen are developing high -tech screening methods with increasing sensitivity to find answers.

In 2017, the team from the US and Europe began to collect and analyze gene samples from wandering dogs inside and around the restricted area. They found many genetic differences in the dog population in the forbidden region compared to dogs living in many neighboring Eastern European countries and even dogs that live about 16 km away in Chernobyl City, according to an article in 2023.

In the 2024 study, Breen and colleagues consider the rising rate at chromosomal level and the genome, even check the nucleotides of dogs, the molecular construction block of DNA. While dogs have experienced 30 generations after the accident, these mutations can be transmitted to pants today. Finally, the search for evidence of a higher mutant rate caused by radioactive exposure causes no results. But this study plays a key role to determine whether genetic changes in dogs in the forbidden area affect the ability to survive and reproduce, according to Christelle Adam-Guillermin, researcher at the particle safety agency. multiply and prevent radiation. Breen shared that the research team would need to take more blood samples in the forbidden area, but his colleagues could not do so since 2020 due to the long war of Russia – Ukraine.

Some species around Chernobyl seem to grow differently. Scientists discovered a higher mutant rate in Daphnia, an extremely small crustacean and bronze rats related to long -term radioactive exposure from the accident. Research from colleagues of Breen is Timothy Mousseau at the University of South Carolina, indicating many signs of increasing mutations, health problems and decreasing the number of living in the forbidden area such as birds, insects and some number. mammalia. However, other research groups did not find radioactive evidence that reduces the number of other animals in the forbidden area, including sheet horns, red deer and wild pigs. Even in high pollution areas, mammals complex seemed to be stable.

The above difference has several explanations, including different research methods, the impact of factors in the surrounding environment and biological differences between species, according to Adam-Guillermin. The reaction of an animal with radioactive depends on many factors such as radioactive sensitivity and the ability to effectively handle DNA lesions, along with specific environments and migration activities.

For example, trees cannot move from the red forest near the Chernobyl factory, so the volume of high radioactive accumulation when absorbing nutrients from the earth, according to Megan Dillon, PhD student at the University of North Carolina Tham Tham Both studies on dogs. This can explain why scientists detect a sudden ratio in pine trees in the banned area.

Meanwhile, recent dogs in the forbidden area often interact with people working in the area around the factory, currently has relatively low radioactive amounts. In fact, the research team did not find any special evidence of radioactive exposure in dogs when using the whole body test, according to Norman Kleiman, the environmental health scientist at the University of Columbia.

Currently, the cause of genetic differences between dog populations has not been clarified. A feasible explanation is that in the small population, such as dogs in the forbidden area, some gene versions may fluctuate randomly in the phenomenon called Genetic Adventure, leading to a few characteristics that disappear from the population. Or become extremely popular, helping to explain the unique gene structure in these dogs. Another possibility is that naturally selective dogs can protect themselves from toxins in the area. “As a consequence from the disaster that occurred 39 years ago, the dogs survived for some reason,” Breen said.