纤细病毒属病毒的分子生物学研究进展

Advances in research on molecular biology of tenuiviruses

纤细病毒属（Ｔｅｎｕｉｖｉｒｕｓ）病毒粒体呈丝状，由核衣壳蛋白和基因组ＲＮＡ 组成．到目前为止，水稻条纹病毒基因组所有４个片段、水稻草状矮化病毒所有６个片段以及水稻白叶病毒和玉米条纹病毒除ＲＮＡ１外的其余片段的核苷酸序列已经测定．各成员所有ＲＮＡ 片段末端均具有共同的保守序列，并且两端互补配对形成锅柄结构．病毒基因组主要采取双义编码策略，但大部分可能编码蛋白的功能未知． ｍ ＲＮＡ 的转录可能采用了抓帽机制．纤细病毒属与白蛉热病毒属、番茄斑萎病毒属在基因组序列、结构和编码策略上的相似性表明，纤细病毒属可能归属于布尼安病毒科（Ｂｕｎｙａｖｉｒｉｄａｅ）．

The tenuiviruses are thread like and composed of a nucleocapsid protein and genomic RNA segments. By far 4 genomic RNA segments of rice stripe virus, 6 of rice grassy stunt virus, 3 of rice hoja blanca virus and 4 of maize stripe virus have been sequenced. All the RNA segments share the conserved terminal sequences, each forming a stable base paired panhandle structure by the complementarity between the 5′ and 3′ termini. The genomic segments mainly use the ambisense coding strategy, but the functions of most putative proteins are unknown. Cap snatching mechanism might be involved in the mRNA transcription. The similarity between tenuiviruses and phloboviruses, tospoviruses in genomic nucleotide sequences, structures and coding strategies suggests that Tenuivirus might be a new genus of Bunyaviridae .