This weeks #FactFriday we are diving deeper into the world of the tardigrade belonging to the phylum tardigrada which comprises over 1,100 species!
These little creatures are usually around 1mm long and have a well-formed head and body consisting of 4 segments, each with a pair of feet with claws or suction discs attached.
Tardigrades are commonly found on lichen, mosses, leaf litter and marine and freshwater sediment all over the world. They can live from hot springs in the Himalayas to the Antarctic and have been found to survive in space. While not being classed as extremophiles (due to them entering a state of cryptobiosis, known as a “tun”) they can survive extreme temperatures, pressures, radioactivity and desiccation.
Most tardigrades are plant eaters and feed by piercing a plant cell with their stylets. Some species are carnivores, feeding on bacteria and even other smaller tardigrade species. While most species only live 3-4 months, some can live for up to 2 years.
DNA sequencing revealed tardigrades to have 75-800 mega-base pairs. The genome of the most stress tolerant species, Ramazzottius varieornatus, was sequenced in 2015 who found that ~1.2% of it’s genes were a result of horizontal gene transfer from bacteria. They also found evidence of a damage suppressor gene (Dsup) which was shown to protect against DNA damage from X-ray radiation. When the team then applied the Dsup protein to human cells, it was found to prevent damage of cells to X-ray radiation by around 40%. #tardigrade