title: Evidence for particle-induced horizontal gene transfer and serial transduction between bacteria.
abstract: Incubation of the amino acid-deficient strain Escherichia coli AB1157 with particles harvested from an oligotrophic environment revealed evidence of horizontal gene transfer (HGT) with restoration of all deficiencies in revertant cells with frequencies up to 1.94 × 10(-5). None of the markers were preferentially transferred, indicating that the DNA transfer is performed by generalized transduction. The highest gene transfer frequencies were obtained for single markers, with values up to 1.04 × 10(-2). All revertants were able to produce particles of comparable size, appearing at the beginning of the stationary phase. Examination of the revertants using electron microscopy showed bud-like structures with electron-dense bodies. The particles that display the structural features of membrane vesicles were again infectious to E. coli AB1157, producing new infectious particles able to transduce genetic information, a phenomenon termed serial transduction. Thus, the <0.2-μm particle fraction from seawater contains a particle size fraction with high potential for gene transfer. Biased sinusoidal field gel electrophoresis indicated a DNA content for the particles of 370 kbp, which was higher than that of known membrane vesicles. These findings provide evidence of a new method of HGT, in which mobilizable DNA is trafficked from donor to recipient cells via particles.
authors.affiliation: Marine Microbiology Laboratory, Department of Marine Ecosystems Dynamics, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: Hiroshi Xavier
authors.initials: HX
authors.lastname: Chiura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kogure
authors.forename: Sylvia
authors.initials: S
authors.lastname: Hagemann
authors.forename: Adolf
authors.initials: A
authors.lastname: Ellinger
authors.forename: Branko
authors.initials: B
authors.lastname: Velimirov
mesh_terms: D001435:Bacteriophages / Q000502:physiology; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D022761:Gene Transfer, Horizontal; D050296:Microbial Viability; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D012623:Seawater / Q000032:analysis; D014161:Transduction, Genetic
chemical_list: D004269:DNA, Bacterial