title: Chemotaxis without Conventional Two-Component System, Based on Cell Polarity and Aerobic Conditions in Helicity-Switching Swimming ofSpiroplasma eriocheiris.
abstract: Spiroplasma eriocheirisis a pathogen that causes mass mortality in Chinese mitten crab,Eriocheir sinensis.S. eriocheiriscauses tremor disease and infects almost all of the artificial breeding crustaceans, resulting in disastrous effects on the aquaculture economy in China.S. eriocheirisis a wall-less helical bacterium, measuring 2.0 to 10.0 μm long, and can swim up to 5 μm per second in a viscous medium without flagella by switching the cell helicity at a kink traveling from the front to the tail. In this study, we showed thatS. eriocheirisperforms chemotaxis without the conventional two-component system, a system commonly found in bacterial chemotaxis. The chemotaxis ofS. eriocheiriswas observed more clearly when the cells were cultivated under anaerobic conditions. The cells were polarized as evidenced by a tip structure, swimming in the direction of the tip, and were shown to reverse their swimming direction in response to attractants. Triton X-100 treatment revealed the internal structure, a dumbbell-shaped core in the tip that is connected by a flat ribbon, which traces the shortest line in the helical cell shape from the tip to the other pole. Sixteen proteins were identified as the components of the internal structure by mass spectrometry, including Fibril protein and four types of MreB proteins.
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal UniversityJiangsu, China; Department of Biology, Graduate School of Science, Osaka City UniversityOsaka, Japan.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai Shanghai, China.
authors.forename: Huajun
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University Jiangsu, China.
authors.forename: Qingguo
authors.initials: Q
authors.lastname: Meng
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University Osaka, Japan.
authors.forename: Natsuho
authors.initials: N
authors.lastname: Terahara
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University Jiangsu, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gu
authors.affiliation: Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai Shanghai, China.
authors.forename: Shengyue
authors.initials: S
authors.lastname: Wang
authors.affiliation: Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai Shanghai, China.
authors.forename: Guoping
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Department of Physics, Gakushuin University Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nakane
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University Jiangsu, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City UniversityOsaka, Japan; The OCU Advanced Research Institute for Natural Science and Technology, Osaka City UniversityOsaka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Miyata
keywords: Fibril; MreB; anaerobic; crab pathongen; cytoskeleton; genome; mass spectrometry; reversal behavior