猪博卡病毒非结构蛋白NP1基因的克隆及基因分型研究

为明确猪博卡病毒福建株非结构蛋白NP1的特征,本研究根据GenBank中登录的非结构蛋白NP1的基因特征,设计特异性引物从一份患有断奶仔猪多系统衰竭综合征的仔猪肺脏和淋巴结基因组DNA中扩增到猪博卡病毒非结构蛋白NP1的全长基因序列。测序结果显示,本试验克隆的猪博卡病毒非结构蛋白NP1的基因全长为675bp,编码有224个氨基酸,其与美国株猪博卡病毒(OH110株)核苷酸同源性最高,达97.3%,但与美国株猪博卡病毒(IN109-1株)核苷酸同源性仅为81.8%;与英国北爱尔兰野猪博卡病毒(F41株和64-1株)同源性均不高,分别为82.5%和80.9%;与猪博卡病毒(H18株)核苷酸同源性最低,仅为43.8%。通过对猪博卡病毒代表株进行核苷酸同源性比对分析发现,猪博卡病毒存在3个主要的基因群,不同基因群非结构蛋白NP1的核苷酸同源性均低于50.0%。结果提示需对猪博卡病毒进行明确的划分,不同来源的猪博卡病毒可细分为3个明显的代表种。

Cloning and Genotyping Classification of Nonstructural Protein NP1 Gene of Porcine Bocavirus

In order to demonstrate the nonstructural proteins 1 (NP1) molecular characterization,the target fragments was obtained from post-weaning multisystemic wasting syndrome piglets using PCR method with specific primers,targeting to the NP1 fragments.The results showed that the porcine bocavirus NP1 gene was 675 bp in length,coding an open reading frame (ORF) with 224 amino acids.The nucleotide sequence were compared with the porcine bocavirus NP1 downloaded from GenBank using MegAlign.The sequenced gene shared the highest homologies of nucleotides with the USA porcine bocavirus OH110 strain at 97.3%,and only shared 81.8% identity to IN109-1 strain; which shared the homogeneity with the United Kingdom porcine bocavirus F41 strain and 64-1 strain at 82.5% and 80.9%,respectively.However,the cloned sequence only shared the homologies of nucleotides with porcine bocavirus H18 strain at 43.8%.According to the phylogenetic tree,the porcine bocavirus could be divided into three genotypes,all of which the homologies of nucleotides were lower than 50.0%.The results suggested that the porcine bocavirus could be divided into three different genus in genus bocavirus.