新疆旱獭肠道RNA病毒的宏转录组学研究

Meta-transcriptomics profiling of Marmota rectal virome in Xinjiang

目的了解新疆地区旱獭(Marmota)肠道携带RNA病毒的病原本底。方法采用宏转录组学方法对新疆喀什地区14只健康旱獭肠道样品进行病毒组分析。结果基于重叠序列(contig)水平共注释到5个脊椎动物病毒科,分别为星状病毒科、小RNA病毒科、呼肠孤病毒科、圆环病毒科和腺病毒科。根据病毒宏转录组学结果,对注释到的病毒进行检测与进化分析,发现心病毒、嵴病毒、摩萨病毒与参考毒株同源性较高,为这些病毒变异株,而肠道病毒、腺病毒与已知病毒具有明显的遗传差异,可能为该病毒新种;星状病毒与其他旱獭源星状病毒之间氨基酸同源性差异较大,显示星状病毒在旱獭体内具有遗传多样性。值得注意的是,旱獭轮状病毒与牛轮状病毒核苷酸同源性高达92%,表明该病毒可能经过粪口途径实现跨种传播。结论该研究揭示了旱獭肠道携带RNA病毒的多样性,为了解旱獭病毒本底、监测病毒传播生态链提供了重要数据。

Objective To find out about the background of RNA virome harbored by Marmota(marmots)in Xinjiang.Methods The intestinal samples of 14 healthy marmots from Kashgar,Xinjiang,were analyzed using the meta-transcriptomics method. Results Five mammalian viral families were annotated based on contig levels,including Astroviridae,Picornaviridae,Reoviridae,Circoviridae and Adenoviridae. According to the results of viral meta-transcriptomics,the detection and evolutionary analysis of the annotated viruses showed that the contigs of cardiovirus,kobuvirus and mosavirus shared high identities with the current known viruses and represented new variants of those viruses. However,the enteroviral and adenoviral contigs showed a distant relationship with known viruses,hence the possibility of new species. There were significant differences in amino acid homology between the astroviruses and the other marmot-derived astroviruses,indicating genetic diversity of the astroviruses in marmots. It was worthy of note that the rotavirus was closely related to bovine virus with as high as 92% nucleotide identity,indicating fecal-oral transmission. Conclusion These results reveal the diversity of RNA viruses harbored in rectal samples of marmots,which sheds light on the marmot virome and ecological circle of viral transmission between natural reservoirs and livestock.