Tardigrade resistance to space effects (tarse): first results of the mission life on foton-m3

Anhydrobiosis is a highly stable and reversible state of suspended life due to complete organism desiccation. Anhydrobiotic tardigrades show extraordinary resistance to physical and chemical extremes, far exceeding tolerance ranges of active animals. Consistent with these potentialities, the Mission LIFE on Foton M3 - TARSE (TArdigrade Resistance to Space Effects), part of the line ASSC of the ASI MoMa project, aimed to analyse the effects of space environment on this animal model. Four experiments have been carried out using Macrobiotus richtersi. In September 2007 desiccated (in microcosm or on paper) and hydrated tardigrades (fed or starved) have flown on Foton M3 for 12 days, using the facility Biokon (by Kayser Italia). As control, ground experiments miming the flight temperatures are currently running. To date we have complete results about survival and preliminary data on life cycle parameters. The highest survival rate has been obtained for desiccated specimens in microcosm (94.4±4.8%) and on paper (78.9±25.2%), and for hydrated starved animals (60.6±8.3%). The lowest survival rate has been recorded for hydrated fed animals (6.8±9.9%). During the flight: i) active females laid eggs, ii) several eggs hatched, iii) the hatching time was very short, and iv) newborns exhibited normal morphology and behaviour. After the flight, adults laid eggs and the reared newborns reached sexual maturity and laid eggs too. Currently we are analysing: i) genomic DNA quality, ii) Hsp expression, iii) oxidative stress. Studies on genomic DNA quality and oxidative stress will allow us to verify possible radiation effects, while Hsp expression will permit to investigate the role of this bioprotectant. Finally, ground experiments on RPM are settled to verify the eventual effects of microgravity.