传染性法氏囊病毒超强毒株全基因组克隆与序列分析  

Cloning and sequence analysis of the full-length genome of very virulent infectious bursal disease virus

作　　者：柳佳佳 梁海英[1] 曾智勇[1] 汤德元[1] 王彬[1] 边孟婷 黄书 潘向英 田红利 LIU Jiajia;LIANG Haiying;ZENG Zhiyong;TANG Deyuan;WANG Bin;BIAN Mengting;HUANG Shu;PAN Xiangying;TIAN Hongli(College of Animal Science,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学动物科学学院,贵州贵阳550025

出　　处：《中国兽医学报》2024年第7期1394-1400,1407,共8页Chinese Journal of Veterinary Science

基　　金：贵州省科技支撑计划资助项目(黔科合支撑[2021]一般162项目)。

摘　　要：为了解致贵州省某鸡场幼鸡死亡的传染性法氏囊病毒(infectious bursal disease virus,IBDV)GZGY2022分离株的基因组特征、遗传变异及毒株类型,本试验设计引物对其进行全基因组的扩增、克隆、测序,遗传演化和毒株类型分析。结果显示,扩增IBDV全基因组的A、B片段分别为3260、2827bp,分别编码VP2~VP5、VP1基因。该毒株A、B片段与VvIBDV毒株核苷酸序列同源性分别为96.2%~98.7%、87.7%~98.9%,均与NN1172株同源性最高,与其他毒株同源性分别为83.1%~94.7%、90.1%~91.0%。遗传演化及毒株类型结果显示,IBDV毒株按抗原及毒力主要分为6个分支,该毒株A、B片段均聚类在VvIBDV分支,根据新基因型分类方法,该毒株为A3B3基因型。氨基酸序列分析结果表明,该毒株A、B片段分别有3、7处独有的氨基酸位点变异,全基因组编码区与超强毒株有13处一致且独有的特征性氨基酸位点。A片段的VP2序列与超强毒株有19处相同的特征氨基酸,其中高变区222A、242I、253Q、256I、279D、284A、294I、299S是超强毒株的特征性的氨基酸位点,七肽区序列SWSASGS与强毒株一致;B片段的VP1序列与超强毒株有10处相同的特征氨基酸,其中61I、145T、287A是超强毒株的特征性的氨基酸位点,777~782核苷酸序列为GGTGCC,未能形成KpnⅠ限制性内切酶位点,结合三联体位点145/146/147(TEG),则B片段与NN1172株一致,其毒力稍弱于B2型VvIBDV毒株。重组分析结果显示,该毒株序列无断裂和重组位点,未发生重组事件。结果表明,GZGY2022株属于A3B3型非重组超强毒株,特殊氨基酸位点均与VvIBDV分子特征相符。In order to understand the genomic characteristics and genetic variation and strain type of infectious bursal disease virus(IBDV)isolate GZGY2022,which caused the death of chickens in Guizhou farm,primers were designed to amplify the whole genome of the isolate,and genetic evolution and strain type analysis were performed after cloning and sequencing.The results showed that the A and B segments of IBDV genome were 3260,2827bp,respectively,encoding VP2-VP5and VP1genes.The nucleotide sequence homology between the A and B segments of this strain and the VvIBDV were 96.2%-98.7%and 87.7%-98.9%,respectively,which is the highest with NN1172strain,83.1%-94.7%and 90.1%-91.0%with other strains.The results of genetic evolution and strain type study showed that IBDV strains can be divided into 6branches according to antigen and virulence,and the A and B segments of the strain were clustered in the evolutionary branch of VvIBDV,and the strain was A3B3genotype according to the new genotype classification method.The results of amino acid sequence analysis showed that there were 3and 7unique amino acid site variations in the A and B segments of the strain,respectively,and 13unique characteristic amino acid sites in the coding region of the full-length genome were consistent with VvIBDV.The VP2sequence of segment A has 19characteristic amino acid identical with VvIBDV,among which hyper variable regions 222A,242I,253Q,256I,279D,284A,294Iand 299Swere characteristic amino acid sites of the VvIBDV,and the heptapeptide region sequence SWSASGS was consistent with the virulent strain.The VP1sequence of segment B has 10characteristic amino acid identical with VvIBDV,among which 61I,145Tand 287Awere the characteristic amino acid sites of the VvIBDV.In addition,the nucleotide sequence GGTGCC of 777-782did not form the restriction endonuclease site of KpnⅠ,and combined with the triplet site 145/146/147(TEG),the segment B was consistent with the NN1172strain,showed that its virulence was slightly weaker than that of the B2strain of VvIBDV.

关 键 词：传染性法氏囊病毒 超强毒株 全基因克隆 序列分析 

分 类 号：S852.65[农业科学—基础兽医学]