Radiation-resistant worms found near Chernobyl: they can help humanity
Scientists have found worms that can withstand radiation near Chornobyl.
SSPDaily tells about it.
Nearly four decades after the nuclear power plant disaster, a new study by researchers at New York University (NYU) has shown that exposure to chronic radiation has not damaged the genomes of microscopic worms that live there today.
In recent years, researchers have found that some animals living in the Chornobyl exclusion zone are genetically different from their counterparts in other places, raising questions about the impact of chronic radiation on DNA.
"We still don't understand the impact of the disaster on the local population very well," Sophia Tintori of New York University, first author of the new study, said. "Did the sudden environmental change lead to the selection of species or even individuals within a species that are naturally more resistant to ionizing radiation?"
Tintori and her colleagues turned to nematodes, tiny worms with simple genomes and rapid reproduction that make them useful for understanding basic biological phenomena. Armed with Geiger counters and protective gear, the team traveled to Ukraine in 2019 to collect worms from soil samples and rotting fruit.
They collected worms from different parts of the zone where radiation levels were different. Using tourist microscopes, they isolated and grew cultures from each worm. Later, the worms were frozen in a laboratory at New York University.
Matthew Rockman, professor of biology at NYU and senior author of the study, said, "We can cryopreserve the worms and then thaw them out for further study. This means that we can stop evolution in the lab, which is not possible for most other animals and is very valuable when we want to compare animals that have gone through different evolutionary histories."
The team studied 15 worms of the Oscheius tipulae species, comparing their genes with those of five similar worms from other parts of the world. They were surprised to find that the genes of the worms from Chernobyl showed no signs of radiation damage.
Tintori noted, "This does not mean that Chernobyl is safe. It rather means that nematodes are really hardy animals and can survive in extreme conditions. We also don't know how long each of the worms we collected was in the zone, so we can't be sure what level of radiation each worm and its ancestors received over the past four decades."
The researchers wondered whether the lack of a genetic signature might be due to the fact that the worms living in Chornobyl are extremely good at protecting or repairing their DNA. They created a system to compare the growth rate of different worm populations and used it to measure the sensitivity of each worm's offspring to different types of DNA damage.
While there were differences between the worm lines in how well they tolerated DNA damage, these differences did not correspond to the radiation levels at each collection site. This suggests that Chornobyl worms are not necessarily more tolerant to radiation and have not been forced to evolve under the influence of the radioactive landscape.
These findings provide a key to understanding how DNA repair may differ between individuals and may help to better understand natural differences in humans.
"Now that we know which strains of O. tipulae are more sensitive or more tolerant to DNA damage, we can use these strains to study why different people are more likely to be affected by carcinogens than others," Tintori said. "Thinking about how people respond differently to DNA-damaging agents in the environment will help us have a clearer picture of our own risk factors."
As a reminder, mutant wolves from Chernobyl have developed resistance to cancer. American scientists have taken blood samples from animals in the Chornobyl zone to understand how wolves' bodies react to radiation.