抄録
Tardigrades are invertebrate animals, some of which can enter into an ametabolic desiccated state called anhydrobiosis. In this state, tardigrades are extremotolerant and able to survive open space environments characterized by severe vacuum and intense radiation. For these reasons, tardigrades are expected to serve as important model organisms for astrobiological studies, particularly those focusing on how multicellular organisms can withstand the extreme environments of space and the possibility of extraterrestrial multicellular life forms. To develop tardigrades as model organisms, we established a culture system for the tardigrade species Ramazzottius varieornatus, a species that is tolerant to several types of extreme physical and chemical environmental conditions while in an anhydrobiotic, or "tun", state. Based on studies using this culture system and the extremotolerance of this tardigrade in connection with its anhydrobiotic capacity, R. varieornatus is a suitable model organism for astrobiological studies and will provide new insight into the mechanisms underlying the ability of multicellular organisms to tolerate extreme environments.
