中文摘要：

猪繁殖与呼吸综合征病毒（PRRSV）是一种严重影响全球养猪业的重要病原,引起母猪繁殖障碍和生长猪的呼吸道疾病。PRRSV分为基因1型和2型,极易变异和演化,并呈现毒株的多样性与致病性的差异。PRRSV基因组的变异主要集中于非结构蛋白Nsp2编码区、结构蛋白ORF5和ORF3基因。毒株间的重组是PRRSV变异与演化以及新毒株产生的主要机制之一,天然免疫和特异性免疫因素在加速其变异与演化中起着重要的作用。深入理解PRRSV变异与演化的本质以及相关分子机制有助于预防与控制其传播与流行。

英文摘要：

Porcine reproductive and respiratory syndrome virus（PRRSV） is the most important pathogen that severely impacts swine industry worldwide, which causes reproductive failure in sows and respiratory disease in growing pigs. PRRSV is divided into genotype 1 and genotype 2, with characteristics of easy variation and evolution as well as diversified strains and pathogenicity differences. The genetic variation of PRRSV genome is mainly distributed in its nonstructural protein 2-coding region and structural protein genes ORF5 and ORF3. The recombination among different strains is one of the major mechanisms contributing to the variation and evolution and emergence of novel strain of PRRSV, and meanwhile innate and adaptive immunity of pigs play important roles in accelerating its variation and evolution. A better understanding of the nature and mechanism associated with the variation and evolution of PRRSV will be helpful for prevention and control of its transmission and prevalence.