The cucumovirus 2b gene drives selection of inter-viral recombinants affecting the crossover site, the acceptor RNA and the rate of selection.
RNA-RNA recombination is an important pathway in virus evolution and has been described for many viruses. However, the factors driving recombination or promoting the selection of recombinants are still unclear. Here, we show that the small movement protein (2b) was able to promote selection of RNA 1/2-RNA 3 recombinants within a chimeric virus having RNAs 1 and 2 from cucumber mosaic virus, and RNA 3 from the related tomato aspermy virus, along with heterologous 2b genes. The source of the 2b also determined the selection of the acceptor RNA and the crossover site, as well as affecting the rate of selection of the recombinant RNAs. The nature of the RNA 3 also influenced the selection of the recombinant RNAs. A 163-nt tandem repeat in RNA 3 significantly affected the rate of selection of the recombinant RNA, while a single nucleotide within the repeat affected the crossover site. The recombination occurred in a non-random manner, involved no intermediates and probably was generated via a copy-choice mechanism during (+) strand RNA synthesis.
Shi
Bu-Jun
BJ
Australian Centre for Plant Functional Genomics, University of Adelaide, School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA 5064, Australia. bujun.shi@acpfg.com.au
Symons
Robert H
RH
Palukaitis
Peter
P
D001483:Base Sequence; D017124:Conserved Sequence; D003434:Crossing Over, Genetic; D017799:Cucumovirus / Q000235:genetics*; D016679:Genome, Viral; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D011995:Recombination, Genetic; D020080:Tandem Repeat Sequences; D014764:Viral Proteins / Q000378:metabolism*
D012367:RNA, Viral; D014764:Viral Proteins