RNA sequencing data for gamma radiation response in the extremotolerant tardigrade Ramazzottius varieornatus.

Tardigrades are microscopic animals of which terrestrial species are capable of tolerating extreme environments by entering a desiccated ametabolic state known as anhydrobiosis. Intriguingly, they survive high dosage gamma rays (>4,000 Gy), possibly through a mechanism known as cross-tolerance. We hypothesized that anhydrobiosis genes are also regulated during cross-tolerance, thus we submitted Ramazzottius varieornatus to 500 Gy 60Co gamma-ray and conducted time-course low-input RNA-Seq. The gene expression was quantified with RSEM and differential expression was determined with DEseq2. Differentially expressed genes were submitted to gene ontology enrichment analysis with GOStat. The transcriptome dynamically shifted nine hours post-exposure.

Yoshida Y ，Horikawa DD ，Sakashita T ，Yokota Y ，Kobayashi Y ，Tomita M ，Arakawa K ... -  《Data in Brief》

Establishment of a rearing system of the extremotolerant tardigrade Ramazzottius varieornatus: a new model animal for astrobiology.

Horikawa DD ，Kunieda T ，Abe W ，Watanabe M ，Nakahara Y ，Yukuhiro F ，Sakashita T ，Hamada N ，Wada S ，Funayama T ，Katagiri C ，Kobayashi Y ，Higashi S ，Okuda T ... -  《-》

Analysis of DNA repair and protection in the Tardigrade Ramazzottius varieornatus and Hypsibius dujardini after exposure to UVC radiation.

Horikawa DD ，Cumbers J ，Sakakibara I ，Rogoff D ，Leuko S ，Harnoto R ，Arakawa K ，Katayama T ，Kunieda T ，Toyoda A ，Fujiyama A ，Rothschild LJ ... -  《PLoS One》

Tolerance of anhydrobiotic eggs of the Tardigrade Ramazzottius varieornatus to extreme environments.

Horikawa DD ，Yamaguchi A ，Sakashita T ，Tanaka D ，Hamada N ，Yukuhiro F ，Kuwahara H ，Kunieda T ，Watanabe M ，Nakahara Y ，Wada S ，Funayama T ，Katagiri C ，Higashi S ，Yokobori S ，Kuwabara M ，Rothschild LJ ，Okuda T ，Hashimoto H ，Kobayashi Y ... -  《-》

Time-series transcriptomic screening of factors contributing to the cross-tolerance to UV radiation and anhydrobiosis in tardigrades.

Tardigrades are microscopic animals that are capable of tolerating extreme environments by entering a desiccated state of suspended animation known as anhydrobiosis. While antioxidative stress proteins, antiapoptotic pathways and tardigrade-specific intrinsically disordered proteins have been implicated in the anhydrobiotic machinery, conservation of these mechanisms is not universal within the phylum Tardigrada, suggesting the existence of overlooked components. Here, we show that a novel Mn-dependent peroxidase is an important factor in tardigrade anhydrobiosis. Through time-series transcriptome analysis of Ramazzottius varieornatus specimens exposed to ultraviolet light and comparison with anhydrobiosis entry, we first identified several novel gene families without similarity to existing sequences that are induced rapidly after stress exposure. Among these, a single gene family with multiple orthologs that is highly conserved within the phylum Tardigrada and enhances oxidative stress tolerance when expressed in human cells was identified. Crystallographic study of this protein suggested Zn or Mn binding at the active site, and we further confirmed that this protein has Mn-dependent peroxidase activity in vitro. Our results demonstrated novel mechanisms for coping with oxidative stress that may be a fundamental mechanism of anhydrobiosis in tardigrades. Furthermore, localization of these sets of proteins mainly in the Golgi apparatus suggests an indispensable role of the Golgi stress response in desiccation tolerance.

Yoshida Y ，Satoh T ，Ota C ，Tanaka S ，Horikawa DD ，Tomita M ，Kato K ，Arakawa K ... -  《BMC GENOMICS》