Recombination between genomic RNAs of two cucumoviruses under conditions of minimal selection pressure.
Recombination is considered to play a key role in RNA virus evolution; however, little is known about its occurrence under natural conditions. We inoculated tobacco plants with wild-type strains of two closely related cucumovirus species: cucumber mosaic virus (CMV) and tomato aspermy virus (TAV). RNA from the inoculated leaves of doubly-infected plants was tested for the presence of recombination events in an 0.8-kb central portion of the viral RNA3. Using a sensitive and specific RT-PCR procedure, we amplified recombinant segments of RNA3 in 3 of 82 tobacco plants infected with both viruses. In each plant in which recombinant segments were amplified, several different crossover sites were observed, all of which were located within a short stretch of high sequence similarity. Two plants had both CMV-TAV and TAV-CMV recombinants. In all cases, precise homologous recombination had occurred. To the best of our knowledge, this is the first report of interspecific recombination between wild-type plant RNA viruses under conditions of minimal selection pressure in favor of the recombinants.
Aaziz
R
R
Laboratoire de Biologie Cellulaire, INRA-Versailles, Versailles Cedex, 78026, France.
Tepfer
M
M
D001483:Base Sequence; D003434:Crossing Over, Genetic / Q000235:genetics; D017799:Cucumovirus / Q000235:genetics*; D016679:Genome, Viral; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000821:virology; D010947:Plants, Toxic; D012367:RNA, Viral / Q000235:genetics*; D011995:Recombination, Genetic / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012641:Selection, Genetic; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014026:Nicotiana / Q000821:virology
D012367:RNA, Viral