摘要
从西北地区 (陕西、甘肃、青海和新疆 ) 1979～ 1999年发生新城疫鸡群中共分离和收集了 15个毒株 ,经蚀斑纯化、SPF鸡胚增殖得到 9株NDV分离株。致病力测定结果表明 ,除 2株为中强毒外 ,其余均为强毒株。以异硫氰酸胍法提取病毒基因组RNA ,RT_PCR扩增其融合蛋白 (F)基因N端 90 8bp的片段 ,经回收、鉴定后 ,克隆到pGEM_T载体上进行核苷酸序列测定。对各毒株核苷酸及推导的氨基酸进行序列和同源性的比较 ,结果表明所有毒株在该区段没有缺失和插入 ,但有多处碱基置换。各分离毒株之间同源性很高 (平均 96 .8% ) ,与疫苗毒株同源性较低 (82 .5 %～ 85 .8% ) ,而分离自青海省的 3个毒株与其他毒株的同源性均较低 (平均 88.0 % )。以 389bp核苷酸绘制系统发育树 ,证实西北地区的新城疫是由基因型Ⅶc和一个新发现的基因型Ⅸ引起的。
NDV strains isolated from chickens of Northwest of China (Shaanxi,Gansu,Xiangjiang and Qinhai)between 1979 and 1999,9 of them were gotten by plague cloning.Pathogenicity test showed that 2 of them were mesogenic,the others were velogenic.For preparation of RNA,the acid guanidinium_thiocynate method was used,cDNA of 908bp from F gene N terminal were amplified by RT_PCR and cloned into pGEM_T vector.The cDNA was sequenced by Sanger's method.15 NDV strains were compared by nucleotides acid sequences analysis between 519bp F gene(from ATG).There were no deletion and insertion in all strains,but many substitutions.All strains except three strains from Qinghai appeared higher homonology each other,and lower compared with La Sota、V4、B1.Phylogenetic tree of NDV strains were constructed by nucleotide acid sequences of a 389bp region of F gene.64 NDV strains were classified into 9 genetypes(Ⅰ～Ⅸ) and 3 sub genetypes(Ⅶa～Ⅶc).9 NDV isolates of Northwest belonged to genetype Ⅶc and a novel genetype Ⅸ.
出处
《中国预防兽医学报》
CAS
CSCD
2000年第5期351-355,共5页
Chinese Journal of Preventive Veterinary Medicine
基金
自然科学基金重大项目! (398932 90_4)
兽医生物技术国家重点实验室开放课题资助
