引起典型PDNS的PCV-2病原分子特征分析  

Analysis of the molecular characteristics of PCV-2 pathogen causing typical PDNS

作　　者：边孟婷 梁海英[1] 曾智勇[1] 汤德元[1] 王彬[1] 叶泥 柳佳佳 黄书 潘向英 田红利 BIAN Mengting;LIANG Haiying;ZENG Zhiyong;TANG Deyuan;WANG Bin;YE Ni;LIU Jiajia;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,贵阳550025

出　　处：《黑龙江畜牧兽医》2024年第13期66-71,共6页Heilongjiang Animal Science And veterinary Medicine

基　　金：贵州省科技支撑计划项目(黔科合支撑〔2021〕一般162项目)。

摘　　要：为了了解引起贵州省贵定县某猪场育肥猪群出现的典型猪皮炎肾病综合征(PDNS)的PCV-2的分子特征,试验首先对采自该猪场患病猪血清进行PCR扩增和克隆测序,然后采用多种分子生物学软件及网站对PCV-2的基因型、基因结构、推导蛋白等进行研究。结果表明:PCR扩增得到大小为1767 bp的条带,与GenBank中CZ246毒株序列(登录号为MZ995482)的相似性最高,将获得的毒株命名为PCV-2 GZGD2022。PCV-2 GZGD2022株为PCV-2d基因型,与PCV-2d参考株NLControl4(登录号为AY484410)相比,含10个开放阅读框(ORF),缺失ORF8,其ORF5终止密码子提前,大小仅为21 bp。该毒株在基因组第1042位有1个碱基T的缺失,但导致Cap蛋白C末端延伸的是脯氨酸(P)而非赖氨酸(K)。与疫苗株(LG株、DBN-SX07-2株、ZJ株、SH株)相比,在Cap蛋白的抗原表位区有7个特异性突变点(F53I、R59K、A68N、T134N、A190T、A68N、T134N)。上述疫苗株之间磷酸化位点的差异主要集中在Cap蛋白上,在88 aa处多了1个丝氨酸磷酸化位点,在47 aa、134 aa、149 aa处少了1个苏氨酸磷酸化位点,在55 aa和218 aa处少了1个酪氨酸磷酸化位点。Rep蛋白有3个N糖基化位点(23NPS25、256NQT258和286NAT288),Cap蛋白有1个N糖基化位点(143NYS145)。Rep、Cap蛋白为混合型蛋白。此外,Rep、Cap蛋白有一些特殊功能结构域,如前者的PH-LIKE、NACHT等结构域和后者的乙酰化修饰位点(1MTYPR6)与核定位信号(NLS)。说明引起贵州省贵定县某猪场猪群出现典型PDNS的致病株为PCV-2d基因型,该毒株缺失ORF8,编码蛋白的氨基酸、抗原表位和磷酸化位点的改变可能是导致其毒力较强、引起典型PDNS的原因。In order to understand the molecular characterization of the causative strain of typical porcine dermatitis nephritis syndrome(PDNS)that appeared on fattening pig herds in a pig farm in Guiding County,Guizhou Province,in the test,firstly,PCR amplification and clonal sequencing were performed on the serum of diseased pigs collected from the farm;then the genotypes,gene structures,and deduced proteins of the causative strains were investigated by using various molecular biology software and online websites.The results showed that the PCR amplification yielded a band of 1,767 bp in size,which showed the highest similarity to the sequence of strain CZ246(accession number MZ995482)in GenBank;the strain obtained was named PCV-2 GZGD2022.The PCV-2 GZGD2022 strain was a PCV-2d type;it contained 10 open reading frames(ORFs)with a deletion of ORF8 compared to the PCV-2d reference strain NLControl4(accession no.AY484410);it had an advanced stop codon for ORF5 and was only 21 bp in size.This strain had a deletion of base T at position 1,042 of the genome,but it was proline(P)rather than lysine(K)that caused the C-terminal extension of the Cap protein.Compared with the vaccine strains(LG,DBN-SX07-2,ZJ,and SH strains),there were seven specific mutation sites(F53I,R59K,A68N,T134N,A190T,A68N,and T134N)in the antigenic epitope region of the Cap protein.The differences in phosphorylation sites between the vaccine strains above were mainly concentrated in the Cap protein;there was 1 more serine phosphorylation site at 88 aa,1 less threonine phosphorylation site at threonine 47 aa,134 aa,and 149 aa,and 1 less tyrosine phosphorylation site at 55 aa and 218 aa.The Rep protein had three N glycosylation sites(23NPS25,256NQT258 and 286NAT288);the Cap protein had one N glycosylation site(143NYS145).The Rep and Cap proteins were mixed-type proteins.In addition,Rep and Cap proteins had some special functional structural domains,such as PH-LIKE and NACHT in the former and acetylation modification site(1MTYPR6)and nuclear localization signal(

关 键 词：猪圆环病毒2型 猪皮炎肾病综合征 分子特征 CAP蛋白 REP蛋白 

分 类 号：S855.3[农业科学—临床兽医学]