Cloning and sequence analysis of P of NDV strains isolated from pigeon of Shaanxi.

【Objective】 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.【Method】 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.【Result】 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.【Conclusion】 The result indicated that there was evident variation between NDV/Pigeon/ShX/China/2003 and between strains isolated from domestic and abroad.