Cloning and sequence analysis of P of NDV strains isolated from pigeon of Shaanxi | 鸽源新城疫病毒陕西分离株P基因的克隆及序列分析

chinois. 对鸽源新城疫病毒（NDV）陕西分离株P基因进行克隆和序列分析，为研究P基因及V基因的功能奠定基础，并为防治新城疫提供科学依据。参考GenBank发表的NDV基因序列设计1对特异性引物，RT-PCR扩增NDV/Pigeon/ShX/China/2003 P基因的全长片段，并进行克隆、序列测定和分析。NDV/Pigeon/ShX/China/2003 P基因全长1 451 bp，其完整的ORF长度为1 188 bp，编码395个氨基酸。同源性比较可知，NDV/Pigeon/ShX/China/2003与其他分离株P基因的核苷酸序列同源性在63.6%~92.9%，推导的氨基酸序列同源性在67.7%~92.2%。系统发育进化树表明，NDV/Pigeon/ShX/China/2003与鸽源分离株P68亲缘关系最近，与F48E9和La Sota毒株处于进化树的不同分支。NDV/Pigeon/ShX/China/2003与国内外已报道的NDV毒株间存在较大变异。

anglais. In order to provide scientific basis for the prevention and control of outbreak and epidemic of Newcastle disease (ND), the P gene of Newcastle disease virus (NDV) isolated from Pigeon of Shaanxi (NDV/Pigeon/ShX/China/2003) was amplified and the sequence was analyzed. The virus was proliferated by inoculating into the non-immune chicken embryos, and was identified by HA and HI method. A pair of specific primers were designed according to the gene sequence of NDV published in GenBank, and was used to amplify the fragment of P gene (1 451 bp) by RT-PCR method, which was cloned and sequenced. The P gene of NDV/Pigeon/ShX/China/2003 contains 1 451 bp and the open read frame (ORF) contains 1 188 bp, which encodes a polypeptide of 395 amino acids. Nucleotide sequences and deduced amino acids sequences analysis showed: homologous rate of P gene nucleotides and deduced amino acids sequences was 63.6%-92.9% and 67.7%-92.2% respectively. The phylogenetic tree showed that there was a close genetic relationship between the Shaanxi isolate and P68 strain. However NDV/Pigeon/ShX /China/2003, F48E9 and La Sota strains were on the different branches of the phylogenetic tree. The result indicated that there was evident variation between NDV/Pigeon/ShX/China/2003 and between strains isolated from domestic and abroad.