2159-2543 Branko Velimirov and Sylvia Hagemann mge Mobilizable bacterial DNA packaged into membrane vesicles induces serial transduction. Landes Bioscience 2011-05-01 80 - 81 Mobile Genetic Elements 1-1 Landes Bioscience Experiments where the amino acid deficient strain E.coli AB1157 was exposed to a particle fraction harvested from a marine oligotrophic environment, ranging in diameter size between 100-130 nm indicated evidence for horizontal gene transfer resulting in revertant cells with restoration of all genetic deficiencies with frequencies up to 1.94 x 10-5. None of the markers was preferentially transferred indicating that the DNA-transfer is performed by generalized transduction. The highest transfer frequency obtained for single markers was 1.04 x 10-2. All revertant strains were able to produce particles of comparable size that were again infectious, appearing at the beginning of the stationary phase. Ultra structural investigation showed a structural resemblance with membrane vesicles, however, Field Gel Electrophoresis indicated that the DNA content of some of the particles was 370 kbp; much higher than that of the so far known previously described membrane vesicles providing evidence of a new mechanism for horizontal gene transfer. http://dx.doi.org/10.4161/mge.1.1.15724 http://www.landesbioscience.com/journals/mge/article/15724/ article Addendum