title: A novel species of ellipsoidal multicellular magnetotactic prokaryotes from Lake Yuehu in China.
abstract: Two morphotypes of multicellular magnetotactic prokaryotes (MMPs) have been identified: spherical (several species) and ellipsoidal (previously one species). Here, we report novel ellipsoidal MMPs that are ∼ 10 × 8 μm in size, and composed of about 86 cells arranged in six to eight interlaced circles. Each MMP was composed of cells that synthesized either bullet-shaped magnetite magnetosomes alone, or both bullet-shaped magnetite and rectangular greigite magnetosomes. They showed north-seeking magnetotaxis, ping-pong motility and negative phototaxis at a velocity up to 300 μm s(-1) . During reproduction, they divided along either their long- or short-body axes. For genetic analysis, we sorted the ellipsoidal MMPs with micromanipulation and amplified their genomes using multiple displacement amplification. We sequenced the 16S rRNA gene and found 6.9% sequence divergence from that of ellipsoidal MMPs, Candidatus Magnetananas tsingtaoensis and > 8.3% divergence from those of spherical MMPs. Therefore, the novel MMPs belong to different species and genus compared with the currently known ellipsoidal and spherical MMPs respectively. The novel MMPs display a morphological cell differentiation, implying a potential division of labour. These findings provide new insights into the diversity of MMPs in general, and contribute to our understanding of the evolution of multicellularity among prokaryotes.
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Yi-Ran
authors.initials: YR
authors.lastname: Chen
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Hai-Jian
authors.initials: HJ
authors.lastname: Du
authors.forename: Hong-Miao
authors.initials: HM
authors.lastname: Pan
authors.forename: Wen-Yan
authors.initials: WY
authors.lastname: Zhang
authors.forename: Ke
authors.initials: K
authors.lastname: Zhou
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Li
authors.forename: Tian
authors.initials: T
authors.lastname: Xiao
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Wu
mesh_terms: D001483:Base Sequence; D002681:China; D020564:Deltaproteobacteria / Q000145:classification* / Q000235:genetics; D052203:Ferrosoferric Oxide; D020459:Genes, rRNA / Q000235:genetics; D007501:Iron; D060106:Lakes / Q000382:microbiology*; D055944:Magnetosomes / Q000502:physiology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013440:Sulfides
chemical_list: D012336:RNA, Ribosomal, 16S; D013440:Sulfides; C111959:greigite; D007501:Iron; D052203:Ferrosoferric Oxide