title: Extremotolerant tardigrade genome and improved radiotolerance of human cultured cells by tardigrade-unique protein.
abstract: Tardigrades, also known as water bears, are small aquatic animals. Some tardigrade species tolerate almost complete dehydration and exhibit extraordinary tolerance to various physical extremes in the dehydrated state. Here we determine a high-quality genome sequence of Ramazzottius varieornatus, one of the most stress-tolerant tardigrade species. Precise gene repertoire analyses reveal the presence of a small proportion (1.2% or less) of putative foreign genes, loss of gene pathways that promote stress damage, expansion of gene families related to ameliorating damage, and evolution and high expression of novel tardigrade-unique proteins. Minor changes in the gene expression profiles during dehydration and rehydration suggest constitutive expression of tolerance-related genes. Using human cultured cells, we demonstrate that a tardigrade-unique DNA-associating protein suppresses X-ray-induced DNA damage by ∼40% and improves radiotolerance. These findings indicate the relevance of tardigrade-unique proteins to tolerability and tardigrades could be a bountiful source of new protection genes and mechanisms.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Hashimoto
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|Graduate School of Environmental Earth Science, Hokkaido University, Kita 8, Nishi 5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.|Institute for Advanced Biosciences, Keio University, Mizukami 246-2, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan.
authors.forename: Daiki D
authors.initials: DD
authors.lastname: Horikawa
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kuwahara
authors.affiliation: Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kozuka-Hata
authors.affiliation: Genome Biology Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Tadasu
authors.initials: T
authors.lastname: Shin-I
authors.affiliation: Comparative Genomics Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Minakuchi
authors.affiliation: Genome Biology Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Ohishi
authors.affiliation: Comparative Genomics Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Ayuko
authors.initials: A
authors.lastname: Motoyama
authors.affiliation: Comparative Genomics Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Aizu
authors.affiliation: Laboratory of Molecular Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Enomoto
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Koyuki
authors.initials: K
authors.lastname: Kondo
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Sae
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Phyloinformatics Unit, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, Hyogo 650-0047, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Hara
authors.affiliation: Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Kita 10, Nishi 5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.|The Hakubi Center for Advanced Research and Graduate School of Science, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Koshikawa
authors.affiliation: Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sagara
authors.affiliation: Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Kita 10, Nishi 5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Miura
authors.affiliation: Laboratory of Extremophiles, Department of Applied Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Yokobori
authors.affiliation: Laboratory of Molecular Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Miyagawa
authors.affiliation: Department of Computational Biology and Medical Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Kubo
authors.affiliation: Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Oyama
authors.affiliation: Genome Biology Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kohara
authors.affiliation: Comparative Genomics Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.|Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Asao
authors.initials: A
authors.lastname: Fujiyama
authors.affiliation: Institute for Advanced Biosciences, Keio University, Mizukami 246-2, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan.
authors.forename: Kazuharu
authors.initials: K
authors.lastname: Arakawa
authors.affiliation: Database Center for Life Science, 178-4-4 Wakashiba, Kashiwa, Chiba 277-0871, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Katayama
authors.affiliation: Comparative Genomics Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Toyoda
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Takekazu
authors.initials: T
authors.lastname: Kunieda
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D004249:DNA Damage; D022761:Gene Transfer, Horizontal; D016678:Genome; D057809:HEK293 Cells; D006801:Humans; D020675:Peroxisomes; D013312:Stress, Physiological / Q000235:genetics; D058467:Tardigrada / Q000235:genetics*; D014965:X-Rays