RESUMO
Although RNA viruses evolved the mechanisms of specific encapsidation, miss-packaging of cellular RNAs has been reported in such RNA virus systems as flock house virus or cucumber necrosis virus. To find out if brome mosaic virus (BMV), a tripartite RNA virus, can package cellular RNAs, BMV was propagated in barley and in Nicotiana benthamiana hosts, purified by cesium chloride (CsCl) gradient ultracentrifugation followed by nuclease treatment to remove any contaminating cellular (host) RNAs. The extracted virion RNA was then sequenced by using next-generation sequencing (NGS RNA-Seq) with the Illumina protocol. Bioinformatic analysis revealed the content of host RNAs ranging from 0.07% for BMV extracted from barley to 0.10% for the virus extracted from N. benthamiana. The viruses from two sources appeared to co-encapsidate different patterns of host-RNAs, including ribosomal RNAs (rRNAs), messenger RNAs (mRNAs) but also mitochondrial and plastid RNAs and, interestingly, transposable elements, both transposons and retrotransposons. Our data reveal that BMV virions can carry host RNAs, having a potential to mediate horizontal gene transfer (HGT) in plants.
Assuntos
Bromovirus/genética , Sequenciamento de Nucleotídeos em Larga Escala , RNA Viral/genética , Montagem de Vírus/genética , Proteínas do Capsídeo/genética , Elementos de DNA Transponíveis/genética , Transferência Genética Horizontal , Hordeum/virologia , Interações Hospedeiro-Patógeno/genética , RNA Mensageiro/genética , Nicotiana/virologia , Vírion/genéticaRESUMO
Accurate forms for the LP(nm) modes (n = 0 and n ⧠2) in a uniform circular-core curved fiber are given. We show that the LP(nm) modes (n ⧠2) are composed of two spatially orthogonal components and that, to the zeroth order, there is no special polarization axis for the LP modes in a uniform circular-core curved fiber.
