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The authors of the research hope that their insights can be used to help protect astronauts from radiation during various space missions.
A team of researchers has sequenced the genome of a newly discovered species of tardigrades (Hypsibius henanensis), revealing how they are able to withstand high doses of radiation.
Tardigrades are quite popular for their ability to survive in extreme environments. Also known as water bears, these creatures have the ability to survive radiation levels approximately 1,000 times the lethal dose for humans. While there are about 1,500 species of tardigrades, only a handful of them have been well studied, Nature reports.
To learn more about its remarkable abilities, a team of scientists has sequenced the genome of one of the new species, revealing some of the molecular mechanisms that give them such extraordinary flexibility. The study, titled “Multi-omics landscape and the molecular basis of radiation tolerance in tardigrades,” was published in Science. These scientists are affiliated with many institutions in China.
The study has identified thousands of tardigrade genes that become more active when exposed to radiation. This shows how the DNA of microscopic animals is protected from damage caused by radiation, in addition to repairing any breaks that do occur.
The authors of the research hope that these insights can one day be used to protect astronauts from radiation during various space missions, as well as clean up nuclear pollution and improve cancer treatments.
“This discovery could help improve the stress tolerance of human cells, which would benefit patients undergoing radiation therapy,” study co-author Lingqiang Zhang, a molecular and cellular biologist at the Beijing Institute of Lipomics, told Nature. “
The new species of tardigrade was discovered by Zhang and his team when they collected moss samples from Funiu Mountain in China's Henan province.
Under the microscope, he learned about a previously unknown species of tardigrade and later named it “Hypsibius henanensis”. A genome sequencing later revealed that this species had a total of 14,701 genes, 30% of which were unique to tardigrades.
As researchers exposed Hypsibius henanensis to radiation doses of 200 and 2,000 grays, they observed 2,801 genes involved in cell division and immune responses as well as DNA repair.
In addition, the research team estimates that 0.5 to 3.1% of tardigrades' genes have been acquired from other organisms – a process called horizontal gene transfer.
Specifically, the study found three key factors that help avoid exposure to radiation. First, its ability to repair DNA even after it has been damaged by radiation.
The second involves a gene that becomes activated when exposed to radiation. As Phys.org reports, this resulted in the formation of two proteins that “are known to be important for the mitochondrial synthesis of ATP – in tardigrades, they appear to also help with DNA repair.”
The last thing was the creature's ability to reduce the damage by producing large numbers of proteins that further served as effective antioxidants.