Tardigrades, also known as water bears, are the most radiation-tolerant animals on Earth. They can withstand extreme environments, such as spaceflight.
Past studies have shown that tardigrades possess robust DNA repair capabilities to endure extreme environments. They produce a protein called damage suppressor (Dsup), which helps protect their DNA from radiation damage. This protein is expressed in human cells and offers some protection. However, the exact mechanisms behind tardigrades’ exceptional resistance to radiation are still not fully understood.
In a new study, scientists identified a new tardigrade species and obtained essential insights into the animal’s ability to endure radiation.
A new understanding of how tardigrades are protected in extreme conditions
The study describes roughly 1,500 species- Hypsibius henanensis. Using genome, transcriptome, and proteome analyses, scientists investigated how these organisms respond to radiation treatment.
The scientists studied how heavy ion radiation affected the animal’s molecular profiles, finding that 285 stress-related genes were upregulated. They also identified three molecular mechanisms contributing to organisms’ ability to tolerate radiation.
The researchers identified three key factors contributing to radiation resistance in tardigrades:
- DOPA dioxygenase 1 (DODA1): A horizontally transferred bacterial gene that produces betalains, pigments with strong free radical scavenging properties.
- Tardigrade-specific protein TDP1: This protein helps repair DNA double-strand breaks.
- Mitochondrial chaperone gene BCS1: This gene, which expanded during tardigrade evolution, is upregulated in response to radiation and helps protect cells from radiation-induced mitochondrial damage.
Introduced tardigrade proteins slows human cell metabolism
The authors noted, “Extreme environmental resistance of extremophiles such as tardigrades is a treasure trove of unexplored molecular mechanisms of stress resistance.”
“Functional research on these radiotolerance mechanisms… will further broaden our understanding of cellular survival under extreme conditions and may inspire promoting human health and combating disease.”
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Journal Reference:
- Lei Li, Zhengping Ge, Shihao Liu et al. Multi-omics landscape and molecular basis of radiation tolerance in a tardigrade. Science. DOI: 10.1126/science.adl0799