Direct visualization of horizontal gene transfer.
Conjugation allows bacteria to acquire genes for antibiotic resistance, novel virulence attributes, and alternative metabolic pathways. Using a fluorescent protein fusion, SeqA-YFP, we have visualized this process in real time and in single cells of Escherichia coli. We found that the F pilus mediates DNA transfer at considerable cell-to-cell distances. Integration of transferred DNA by recombination occurred in up to 96% of recipients; in the remaining cells, the transferred DNA was fully degraded by the RecBCD helicase/nuclease. The acquired integrated DNA was tracked through successive replication rounds and was found to occasionally split and segregate with different chromosomes, leading to the inheritance of different gene clusters within the cell lineage. The incidence of DNA splitting corresponds to about one crossover per cell generation.
Babic
Ana
A
INSERM U571, Paris F-75015, France.
Lindner
Ariel B
AB
Vulic
Marin
M
Stewart
Eric J
EJ
Radman
Miroslav
M
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D043211:Exodeoxyribonuclease V / Q000378:metabolism; D022761:Gene Transfer, Horizontal; D008164:Luminescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D018933:Pili, Sex / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011995:Recombination, Genetic
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; C089746:SeqA protein, E coli; C054562:yellow fluorescent protein, Bacteria; D043211:Exodeoxyribonuclease V