da Fonseca Guilherme Cordenonsi, de Oliveira Luiz Felipe Valter, de Morais Guilherme Loss, Abdelnor Ricardo Vilela, Nepomuceno Alexandre Lima, Waterhouse Peter M, Farinelli Laurent, Margis Rogerio
Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, RS, Brazil.
Departamento de Genética, Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, RS, Brazil.
Plant Sci. 2016 May;246:62-69. doi: 10.1016/j.plantsci.2016.01.011. Epub 2016 Feb 11.
Horizontal gene transfer (HGT) is known to be a major force in genome evolution. The acquisition of genes from viruses by eukaryotic genomes is a well-studied example of HGT, including rare cases of non-retroviral RNA virus integration. The present study describes the integration of cucumber mosaic virus RNA-1 into soybean genome. After an initial metatranscriptomic analysis of small RNAs derived from soybean, the de novo assembly resulted a 3029-nt contig homologous to RNA-1. The integration of this sequence in the soybean genome was confirmed by DNA deep sequencing. The locus where the integration occurred harbors the full RNA-1 sequence followed by the partial sequence of an endogenous mRNA and another sequence of RNA-1 as an inverted repeat and allowing the formation of a hairpin structure. This region recombined into a retrotransposon located inside an exon of a soybean gene. The nucleotide similarity of the integrated sequence compared to other Cucumber mosaic virus sequences indicates that the integration event occurred recently. We described a rare event of non-retroviral RNA virus integration in soybean that leads to the production of a double-stranded RNA in a similar fashion to virus resistance RNAi plants.
水平基因转移（HGT）是基因组进化中的一种主要力量。真核生物基因组从病毒获取基因是HGT的一个研究充分的例子，包括非逆转录RNA病毒整合的罕见情况。本研究描述了黄瓜花叶病毒RNA - 1整合到大豆基因组中的情况。在对来自大豆的小RNA进行初步的宏转录组分析后，从头组装得到了一个与RNA - 1同源的3029个核苷酸的重叠群。通过DNA深度测序证实了该序列在大豆基因组中的整合。整合发生的位点包含完整的RNA - 1序列，随后是一个内源性mRNA的部分序列以及另一个作为反向重复的RNA - １序列，并允许形成发夹结构。该区域重组到位于大豆基因一个外显子内的逆转座子中。与其他黄瓜花叶病毒序列相比，整合序列的核苷酸相似性表明该整合事件是最近发生的。我们描述了大豆中一种罕见的非逆转录RNA病毒整合事件，该事件以与抗病毒RNA干扰植物类似的方式导致双链RNA的产生。
