阅读说明：本技术 一种重组马立克病毒mdlv21株的构建及应用 (Construction and application of recombinant Marek's virus MDLV21 strain ) 是由 苏帅 崔宁 成子强 王淑雯 李久庆 于 2021-08-23 设计创作，主要内容包括：本发明涉及一种重组马立克病毒MDLV21株的构建及应用。所构建的重组病毒同时缺失了MDV致病、致肿瘤相关的两个主要基因RLORF6、Meq和CmR基因,相比缺失单一基因,极大增加了疫苗安全性,降低了野外获得缺失基因的能力；重组病毒株基因组没有抗性基因,符合国内外生物制品行业的严格要求；重组病毒具有良好的生物安全性,具有更为有效的抗MDV的免疫保护效果,尤其适用我国鸡群MDV的免疫。重组病毒能够有效的与野毒进行区分,并且其水平传播能力较弱,不仅对鸡群MDV的免疫具有极大的应用价值,更是有利于推进MDV的净化,重组病毒株基因组没有FRT序列,减少了外源基因对病毒生物学活性的影响,避了FRT序列间病毒基因片段的任意剪切,更有利于研制重组活病毒载体疫苗。(The invention relates to construction and application of a recombinant Marek's virus MDLV21 strain. The constructed recombinant virus simultaneously deletes two main genes RLORF6, Meq and CmR related to MDV pathogenicity and tumorigenesis, compared with a deletion single gene, the vaccine safety is greatly improved, and the capacity of obtaining the deletion gene in the field is reduced; the recombinant virus genome has no resistance gene and meets the strict requirements of the biological product industry at home and abroad; the recombinant virus has good biological safety, has more effective immune protection effect against MDV, and is particularly suitable for the immunization of the MDV of chicken flocks in China. The recombinant virus can be effectively distinguished from wild virus, and has weaker horizontal transmission capability, thereby having great application value to the immunity of chicken MDV, being more beneficial to promoting the purification of MDV, reducing the influence of exogenous genes on the biological activity of the virus, avoiding the random shearing of virus gene segments among FRT sequences, and being more beneficial to developing recombinant live virus vector vaccines.)