TARDIKISS: tardigrades in the mission STS-134, the last of the shuttle Endeavour

The TARDIKISS project (Tardigrades in Space) investigates the physiological and molecular effects of space stresses on alive desiccated multicellular organisms, the tardigrades. It is a part of the Biokis (Biokon in Space), a set of multidisciplinary experiments of DAMA (DArk MAtter) mission on board of STS-134 space flight, the last of the shuttle Endeavour, in the frame of a joint between ASI and Italian Air Force. In TARDIKISS, experimentally desiccated (anhydrobiotic) specimens of Paramacrobiotus richtersi and Ramazzottius oberhaeuseri have been used. Both species have very good anhydrobiotic ability, but differ for several biological and ecological characters. Paramacrobiotus richtersi is carnivorous, soil-dwelling and white in colour, while R. oberhaeuseri is lichen-dwelling, herbivorous, and characterized by a brown/red pigmentation. The experiment units of TARDIKISS were hosted by the Biokon, a standard transportable container designed and manufactured by Kayser Italia. In May 2011, the experiment units of TARDIKISS project have been integrated on Middeck Locker of ISS and have flown for 16 days. As control, ground experiments replicating the temperature profile recorded within the Biokon during the flight are currently running. To this day, we have completed the analysis on tardigrade survival after the space flight and obtained preliminary data on life cycle parameters. Both tardigrade species showed a very high survival (98.33% for P. richtersi and 90.0% for R. oberhaeuseri) and no significant differences were scored between flight or Earth tardigrades. After the flight, specimens of P. richtersi were reared in lab. Females laid eggs with normal shape; several eggs hatched with a short hatching time and newborns exhibited normal morphology and behaviour. In the next step, genomic DNA quality and oxidative metabolism of flown tardigrades vs ground control tardigrades will be analysed.