Recombination of 5' subgenomic RNA3a with genomic RNA3 of Brome mosaic bromovirus in vitro and in vivo.
RNA-RNA recombination salvages viral RNAs and contributes to their genomic variability. A recombinationally-active subgenomic promoter (sgp) has been mapped in Brome mosaic bromovirus (BMV) RNA3 (Wierzchoslawski et al., 2004. J. Virol.78, 8552-8864) and mRNA-like 5' sgRNA3a was characterized (Wierzchoslawski et al., 2006. J. Virol. 80, 12357-12366). In this paper we describe sgRNA3a-mediated recombination in both in vitro and in vivo experiments. BMV replicase-directed co-copying of (-) RNA3 with wt sgRNA3a generated RNA3 recombinants in vitro, but it failed to when 3'-truncated sgRNA3a was substituted, demonstrating a role for the 3' polyA tail. Barley protoplast co-transfections revealed that (i) wt sgRNA3a recombines at the 3' and the internal sites; (ii) 3'-truncated sgRNA3as recombine more upstream; and (iii) 5'-truncated sgRNA3 recombine at a low rate. In planta co-inoculations confirmed the RNA3-sgRNA3a crossovers. In summary, the non-replicating sgRNA3a recombines with replicating RNA3, most likely via primer extension and/or internal template switching.
Plant Molecular Biology Center and Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA.
Joanna
J
Sztuba-Solińska
Aleksandra
A
Dzianott
Jozef J
JJ
Bujarski
D017795:Bromovirus / Q000235:genetics* / Q000378:metabolism; D027465:Chenopodium quinoa / Q000821:virology; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D016679:Genome, Viral; D001467:Hordeum; D010935:Plant Diseases / Q000821:virology; D012367:RNA, Viral / Q000235:genetics*; D016865:Reassortant Viruses
D012367:RNA, Viral