New tardigrade species shows how it survives extreme exposure to radiation

A team of Chinese biologists has discovered how a new tardigrade species, Hypsibius henanensis, can survive extreme exposure to radiation. The research highlights the unique mechanisms within this recently identified tardigrade from Henan Province. Known for their resilience under extreme conditions, they can tolerate environments that would be fatal to most other organisms, even in the harsh vacuum of space.

For this studyresearchers studied H. henanensis for six years to understand its unique radiation resistance. After sequencing the genome, they identified 14,701 genes, almost 30 percent of which were specific to tardigrades. To investigate the response to radiation, they exposed the DNA to different doses of gamma radiation, from low to high levels.

Key factors in radiation resistance

The researchers discovered that approximately 2,801 genes from H. henanensis are involved in DNA repair. They identified three major factors that contribute to this tardigrade’s ability to survive high radiation:

Gamma rays damage DNA by removing electrons from the atoms, ionizing the DNA and sometimes causing strand breaks. H. henanensis can efficiently repair such damage using a protein called TRID1, which is unique to tardigrades. This rapid repair mechanism prevents permanent damage and promotes cell survival.

Activation of mitochondrial proteins for enhanced DNA repair

During exposure to radiation, a certain gene in H. henanensis is switched on. This causes the production of two proteins that normally help synthesize ATP in the mitochondria. In tardigrades, these proteins also appear essential for DNA repair, supporting cells against radiation-induced damage.

The tardigrade produces numerous antioxidant proteins that neutralize free radicals: unstable molecules created by radiation that can further damage cells. By producing these antioxidants, H. henanensis minimizes potential cellular damage.

The study’s findings advance our understanding of molecular resilience and may inform future developments in radiation protection and DNA repair therapies.