Water bears, aka tardigrades, are resilient little creatures. These microscopic animals can survive both freezing and boiling temperatures, radiation, high pressure, starvation, the vacuum of space and even desiccation. This last ability caught the attention of a team of researchers interested in how they are able to survive for years despite being completely dried out, an ability known as anhydrobiosis.
Video by Daiki D. Horikawa, via YouTube.
The team discovered special genes that make proteins to protect the animal’s cells during anhydrobiosis. The proteins created by these genes are called tardigrade-specific intrinsically disordered proteins, or TDPs for short. If these TDP genes are altered, the animals lose the ability to tolerate dessication. These proteins work by creating a matrix that wraps around their cellular molecules. Doing this also slows down their metabolism. Upon rehydration, the proteins melt again and the cells are free to function normally.
TC Boothby, H Tapia, AH Brozena, S Piszkiewicz, AE Smith, I Giovannini, L Rebecchi, GJ Pielak, D Koshland, B Goldstein. Tardigrades Use Intrinsically Disordered Proteins to Survive Desiccation. Molecular Cell. 65(6): p975–984.e5, 16 March 2017.