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1、临床分离鸡毒支原体粘附素蛋白编码基因pvpA的分子特征陈继荣,曾振灵,邓碧琴,阎化领,李旭宁,蒋红霞(华南农业犬学兽医学院/广东省兽药研制与安全评价垂点实验室,广州510642)摘要:【目的】探讨中国临床分离鸡毒支原体粘附素蛋白(PvpA)编码基因的分子特征,为进一步了解鸡毒支原体致病机制、建立新的鉴别诊断方法奠定基础。【方法】利用巢式PCR法对41株广东、四川和北京地区临床分离的鸡毒支原体和3株参考株的00基因进行扩増并测序,分析中国临床分离株pvpA的基因变异特征。【结果】所有临床分离株0”!基因分子特征与强
2、毒株S°,BGe—致,与疫苗株氐完全不同。临床分离株0%彳基因C-末端DR-LDR-2区域(第670位~第1056位)GC的含景为53.52%,明显高于鸡毒支原体的平均GC含量;所有临床分离株及S6、BG纱在DR-1和DR-2之间丢失60个碱基。推测该区域编码的氨基酸序列富含脯氨酸,高达30.27%;重复四Pro-Arg-Pro-X共出现10次,X为甲硫氨酸6次、甘氨酸1次、天冬酰胺1次、谷氨酰胺2次。而疫苗株F.6PvpA只有DR-1区域,与R株相比间隔25狀缺失了24个肽,DR-2区域全部丢失。【结论】临床分
3、离株0卩1基因变异特征与强毒株£一致,与疫苗株F*的变异特征有显著差异,可以把“卩刃基因作为靶标以建立临床鸡毒支原体流行病调查和诊断的新方法。关键词:鸡寿支原体;基因;粘附蛋白;变异MolecularCharacterizationofAdhesin-EncodingGenepvpAAmongIsolatedMycoplasmagallisepticumfromGuangdong,SichuanandBeijingCHENJi-rong,ZENGZhen-Iing,DENGBi-qin,YANHua-ling,L
4、IXu-ning,JIANGHong-xia(CollegeofVeterinaryMedicine,GuangdongKeyLaboratoryforVeterinaryDrugDevelopmentandSafetyEvaluation.SouthChinaAgriculturalUniversity,Guangzhou510642)Abstract:【Objective】ThemolecularcharacterizationoftheMycoplasmagallisepticumpvpAgenewhich
5、encodesaputativecyladhesinproteinwasinvestigated,whichwouldbehelpfulfordevelopinganewdetectionanddiagnosismethodsbyusingthevariablepvpAgeneasthetargetaswellasbetterunderstandingthepathogenicmechanismofM.gallisepticum.【Method]ThepvpAgenesofboth41isolatedgallis
6、epticumfromGuangdong,SichanandBeijingand3referencesM.gallisepticum(Sg.BG44handF36)wereobtainedbynest-PCR,andsequenced・【Resull】IlshowedthatthepvpAgenesof41M.gallisepticiunisolatessharedtheidenticalvariationwithS6,BG44T、andshowedsignificantdifferenceswithliveM・
7、galliseplicumvaccine,F36・TheG+CcontentbetweenDR・1andDR-2ofpvpAgeneC-tcrnimalofallisolateswas53.52%,apparentlyhigherthantheaverageG+CcontentfortheM.gallisepticumgenome.60basesweredeletedwithinDR-1andDR-2among41isolatesaswellasBG44t-Besides,PvpAmoleculeinthisre
8、gionpossessesaproline-richcarboxytidemotif(Pro-Arg-Pro-X)whichrepeated10times,XisMet,Gly,Asn,Glufor6,1,1,2times,respectively.HoweverthePvpAmoleculeoflivevaccineF36wasonlyleftDR-1.24of25pe