鸡传染性法氏囊病病毒反向遗传操作系统的建立及基因功能研究-预防兽医学专业论文.docx

rGt—GxVP4。通过病毒复制动力学试验和对SPF鸡攻毒试验，证nYlVP3与IBDV在CEF上的复制相 rGt—GxVP4。通过病毒复制动力学试验和对SPF鸡攻毒试验，证nYlVP3与IBDV在CEF上的复制相 关(其rrlP981L可能有正向促进作用)：VP3不影响IBDV的毒力：VP4不影响IBDV的毒力以及在 CEF r的复制，对VP3亦无协同作_L}j。 本研究用全新的思路成功构建了RNA polymerase 11介导的IBDV反向遗传操作系统，并对 IBDV VP2、VP3、VP4的功能作了研究，对全面了解IBDV的结构与功能，明确1BDV变异的分 子基础，揭示IBDV致病与免疫的分子机制，探索1BDV分子致弱方法，研发适台于流行毒株的 新型疫苗具有重要意义。 关键词：鸡传染性法氏囊病病毒，Gt株，反向遗传操作，vP2，VP3，基因功能 AbstractInfectious Abstract Infectious bursal disease(IBD)，mediatied by infectious bursal disease virus(IBDV)，is the causative agent of acute and highly contagious disease in 3-6 week-old chickens．The first outbreak of IBD was reported at Gumboro in American in 1957 During the past 50 years，IBD has been threatenned the poultry industry constantly．The immunosuppression，antigenic variation，especially the emergence of very virulent IBDV(wIBDV)，represents a new challenge for effective prevention and control of IBD．Recently，IBD was estimated having considerable socio-economic importance at the international level during the 63“General Session of the Office Intemationnal des Epizooties(OIE， Paris)．The researches about the molecular basis ofthe antigenic variation．virulence and cell tropism of IBDV have been constantly emphasized． In one of our previous researches，the vvlBDV Gx strain was attenuated to Gt strain through continue passage in specific-pathogen flee(SPF)chicken embryos(5 generation)and in chicken embryo fibroblast(CEF)cell cultures(20 generation)．The Gx strain has the motality ofabove 60％and can not adapt to CEF culture．The 9“generation in CEF(named F9)has lower motality and adapt to CEF culture． In this research，the long-accurate PCR(LA-PCR)was developed and the full—length genome of Gt strain was cloned and sequenced，Also，the VP2 gene ofF9 was cloned and sequenced．Compared with Gx，there are two amino acids mutation(Q253H and A284T)in VP2 of F9，and another ten amino acids mutation in VP2 of Gt．Besides．there are four and six amino acids mutation in VP3 and VP4 between strain Gx and G