福建一例HAstV-5型星状病毒的全基因组测序与重组分析

Whole-genomic Analysis of a Recombinant HAstV-5 Astrovirus Identified in Fujian,China

为了探究一例福建省检出的HAstV-5型星状病毒2013/Fuzhou/85毒株基因组分子结构特点,本研究采用PCR分段扩增、测序、拼接的方法,获得2013/Fuzhou/85毒株基因组序列全长6 803bp：5′端和3′端均有85bp非编码区;中间3个开放阅读框：ORF1a长2 802bp（86~2 887nt）,编码非结构蛋白丝氨酸蛋白酶;ORF1b长1 548bp（2 827~4 374nt）,编码非结构蛋白RNA聚合酶;ORF2长2 352bp（4 367~6 718nt）,编码结构蛋白衣壳蛋白前体。目前,GenBank中仅有两株HAstV-5型星状病毒全基因组序列：中国辽宁毒株（JQ403108）和巴西哥亚尼亚毒株（DQ028633）,2013/Fuzhou/85毒株和中国辽宁毒株核苷酸相似度最高,达94.4%。对该HAstV-5型星状病毒3个开放阅读框分别构建系统进化树,发现ORF1a与HAstV-1（JF327666）相似度最高,ORF1b和ORF2与HAstV-5（JQ403108）相似度最高,提示其有可能存在重组,用Simplot软件进行重组分析,重组位点位于2 741bp,在ORF1a和ORF1b重叠区的上游。本研究中对2013/Fuzhou/85毒株的全基因组测序和重组分析,可以为星状病毒的重组和遗传进化规律研究提供参考。

A human strain of astrovirus 5,2013/Fuzhou/85,was detected in Fujian Province,China.The whole genomic sequence of this strain was amplified by reverse transcription-polymerase chain reaction and assembled using SeqMan software.This strain contained 6,803 nucleotides,including 85 bp 5′-UTR,85 bp 3′-UTR,and three open reading frames（ORFs）：ORF1 a（2,802 bp）,ORF1 b（1,548 bp）and ORF2（2,352 bp）.These ORFs encode the viral protease,polymerase and precursor of capsid protein,respectively.GenBank showed two whole-genomic sequences of HAstV-5 astroviruses：the Liaoning strain（JQ403108）and Goiania strain（DQ028633）.The 2013/Fuzhou/85 strain had a similarity of 94.4% with the Liaoning strain.Phylogenetic analyses of the ORFs showed that the ORF1 band ORF2 of the 2013/Fuzhou/85 strain were highly similar to HAstV-5（JQ403108）,however ORF1 a was highly similar to HAstV-1（JF327666）.Simplot analyses indicated the potential recombination point in 2013/Fuzhou/85 strain was upstream of the ORF1 a/ORF1 boverlap.The whole genomic sequence of the 2013/Fuzhou/85 strain could be a reference sequence for the genetic analyses of astroviruses.