摘要
为培育及鉴定马立克氏病病毒(MDV)致弱病毒株,本研究将4株现地流行MDV强毒株(L-ZY、L-CZ、L-MS和L-SY株),在体外经CEF连续传代至110代,获得相应的4株高代次病毒株(L-ZYp110C、L-CZp110C、L-MSp110C和L-SYp110C株)。其中的L-MSp110C和L-SYp110C株对SPF鸡的致病性试验结果显示:以2×103 pfu和2×104 pfu的剂量接种1日龄SPF鸡,在试验期(12周)内试验鸡均没有引起马立克氏病病变;高代次病毒株在体外增殖能力增强,而在体内增殖能力显著低于亲本病毒株。与亲本病毒株基因序列比对发现:4株高代次病毒株病毒基因组中Meq和RLORF12基因均有不同程度的缺失和插入;132 bpr序列拷贝数均显著增加;其中3株病毒株的RLORF4基因存在大片段缺失。以上结果表明,MDV强毒株体外传代至110代后,病毒增殖能力和主要致瘤相关基因的遗传特性均发生了改变,致弱毒株的毒力已完全弱化。该研究为进一步筛选MD弱毒疫苗提供了实验依据。
To attenuate Marek＇s disease virus （MDV）, four MDV virulent strains （L-ZY, L-CZ, L-MS and L-SY） were passed for 110 passages in CEF, designated L-ZYp110C, L-CZp110C, L-MSp110C and L-SYp110C, respectively. The pathogenicity tests of L-MSp110C and L-SYpll0C in SPF chickens shown that the 2 attenuated strains had no any pathogenicity to SPF chickens inoculated with 2 × 103 PFU to 2 × 103 PFU in experimental period of 12 weeks. The titers of the virus increased gradually during serial passage in CEF, on the contrary, the replication capacity decreased in chickens. The sequence analysis results demonstrated that different levels of deletion and insertion were found in Meq and RLORF12 genes of the 4 high-passaged strains alignment with their parental virus strains, and 132 bp copies in RL region of the 4 attenuated strains were significantly increased. Furthermore, large fragment deletions were also found in RLORF4 genes in 3 attenuated strains, but not in L-MSp110C. These results indicated that the 4 high-passaged strains were completely attenuated which provides experimental basis for selection of the condidate vaccine strains against MD.
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
2011年第12期915-919,共5页
Chinese Journal of Preventive Veterinary Medicine
基金
国家重点实验室基本科研业务费(SKLVBP201008)
中央级公益性科研院所基本科研业务费专项(ZGKJ201102)
关键词
马立克氏病病毒
致弱毒株
特性分析
Marek＇s disease virus
attenuated strain
characteristic analysis
