Cell morphology and nucleoid dynamics in dividing Deinococcus radiodurans

• Published in: Nature communications 2019-08, Vol.10 (1), p.3815-13, Article 3815
• Main Authors: Floc’h, Kevin, Lacroix, Françoise, Servant, Pascale, Wong, Yung-Sing, Kleman, Jean-Philippe, Bourgeois, Dominique, Timmins, Joanna
• Format: Article
• Language: English
• Subjects: 14/19; 14/33; 14/35; 14/63; 631/326/41; 631/326/88; 631/80/641; Bacteria; Bacterial Proteins - metabolism; Bacteriology; Cell Cycle; Cell Division; Cell morphology; Cellular Biology; Cocci; Cytology; Deinococcus - physiology; Deinococcus radiodurans; Deoxyribonucleic acid; DNA; DNA, Bacterial - genetics; DNA, Bacterial - metabolism; DNA-Binding Proteins - metabolism; Fluorescence; Fluorescence recovery after photobleaching; Genetic Loci - physiology; Genome, Bacterial - physiology; Genomes; HU protein; Humanities and Social Sciences; Intravital Microscopy; Life Sciences; Microbiology and Parasitology; Microscopy; Microscopy, Fluorescence; Morphology; multidisciplinary; Nucleoids; Organelles - genetics; Organelles - metabolism; Particle tracking; Photobleaching; Science; Science (multidisciplinary); Subcellular Processes
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-11725-5

Our knowledge of bacterial nucleoids originates mostly from studies of rod- or crescent-shaped bacteria. Here we reveal that Deinococcus radiodurans , a relatively large spherical bacterium with a multipartite genome, constitutes a valuable system for the study of the nucleoid in cocci. Using advanced microscopy, we show that D. radiodurans undergoes coordinated morphological changes at both the cellular and nucleoid level as it progresses through its cell cycle. The nucleoid is highly condensed, but also surprisingly dynamic, adopting multiple configurations and presenting an unusual arrangement in which oriC loci are radially distributed around clustered ter sites maintained at the cell centre. Single-particle tracking and fluorescence recovery after photobleaching studies of the histone-like HU protein suggest that its loose binding to DNA may contribute to this remarkable plasticity. These findings demonstrate that nucleoid organization is complex and tightly coupled to cell cycle progression in this organism. Deinococcus radiodurans is a relatively large spherical bacterium with a multipartite genome. Here, the authors study the coordinated morphological changes at the cellular and nucleoid level as the bacteria progress through the cell cycle, showing complex nucleoid organization and dynamics.