不同时期NDV地方株F基因的克隆及序列分析与基因型研究

Genetic Variation and Genotype of Newcastle Disease Virus Isolates in Luoyang Area of Henan Province

利用RT-PCR技术对1998-2002年闯洛阳地区新城疫典型发病禽群中所分离到的15个毒株的F基因主要功能区片段进行了克隆和序列分析，并根据其47～435位核苷酸序列构建了系统进化树，确定了其毒力强弱和基因型。结果显示，依据核苷酸和推导的氨基酸同源性的不同，15个地方毒株可分为3群，群内各毒株同源性较高，群间差异较大，未发现有因分离禽品种不同所引起的明显的株间差异。其中第1群9株，涉及到各时间段分离的毒株和所有分离禽品种，属典型的基因Ⅶ型强毒株，高度集中于进化树的基因Ⅶ型C亚型区；第2群4株，属传统的基因Ⅵ型强毒株。分散于进化树的基因Ⅵ型区；第3群2株，属古典基因Ⅱ型的弱毒株，分散于进化树的基因Ⅱ型区。结果表明，近年来该地区流行的新城疫病毒以新的基因Ⅶ型为主，同时兼有传统的基因Ⅵ型和古老的基因Ⅱ型；并提示基因Ⅶ型各毒株在该地区流行的时间较短，株间差异不大。

Main function fragment of fusion gene of 15 NDV strains were amplified by reveres transcriptionpolymerase chain reaction（RT-PCR） and sequenced after being cloned into pMD-18-T plasmids. By means of sequence analysis ,the phylogenetic tree was constructed based on the obtained nucleotide（from 47 to 435 bp）,and the virulence and genotype of the 15 NDV strains were confirmed. The results showed that the 15 isolates can be divided into three groups. The nucleotide sequence and deduced amino acid sequence of this fragment of the 15 NDV strains were compared with those of published NDV F genes respectively. Their homology was higher in the same group and lower between the groups,no difference caused by breed was found in this test. There were 9 strains in the first group,4 strains in the second group and 2 strains in the third group. The NDV strains in group 1,2,3 belonged to genotype Ⅶ, Ⅵ and Ⅱ ,respectively. It revealed that the ND epidemic in Luoyang area were caused mainly by the new genotype Ⅶ strains,moreover,the traditional genotype Ⅵ and Ⅱ strains were also responsible for the ND prevalence.