根据猪繁殖和呼吸综合征病毒(PRRSV)已发表的核苷酸序列,设计了1对特异性引物P1/P2,用RT-PCR扩增了PRRSV福建毒株FJ-1和FJ-2的全长核衣壳蛋白基因(ORF7),将扩增产物连接到pUCm-T载体并转化大肠杆菌DH10B,提取阳性重组质粒进行序列测定与分析.结果表明:FJ-1和FJ-2毒株ORF7基因均为372 bp,编码123个氨基酸,与美洲型参考毒株VR-2332及欧洲型参考毒株LV的核苷酸同源性分别为95.16%,94.35%和61.40%,60.65%,其推导的氨基酸同源性分别为95.93%,95.12%和56.49%,55.73%.研究表明,福建流行的FJ-1和FJ-2属于美洲型PRRSV毒株.Porcine Reproductive and Respiratory Syndrome Virus(PRRSV) strains FJ-1 and FJ-2 were isolated from a pig farm in Fujian province of China during an outbreak of PRRS.The full-length of ORF7 gene encoding the nucleocapsid protein(N) protein of FJ-1 and FJ-2 was amplified by RT-PCR with a pair of primers(P1/P2) and cloned into pUCm-T vector,and transformed to E.coli DH10B competent cell.The purified recombinants were subjected to sequencing and analysis.The ORF7 genes of FJ-1 and FJ-2 were both 372 bp and encoding 123 amino acids.They displayed 95.16 %,94.35 % and 61.40 %,60.65 % nucleotide identities to strains VR-2332(a reference strain of America) and LV(European genotype),respectively.The deduced amino acids of FJ-1 and FJ-2 showed 95.93 %,95.12 % and 56.49 %,55.73 % identities to strains VR-2332 and LV.The results shown here strongly suggested that PRRSV strains FJ-1 and FJ-2 belong to American genotype.福建省科技攻关计划重点项目(2003N083);; 厦门市科技攻关计划重点项目(3502Z20031054
