| The six-strain Newcastle Disease Virus were isolated from the chickens and pigeon of poultry farm in Xinjiang. The results of Hemagglutination (HA) test and Hemagglutination Inhabition (HI) test indicated that the six-strain NDV have HA. The HA of six-strain NDV all can be inhibited by ND positive serum and can't be inhibited by AI (H5 subtype and H9 subtype) positive serum.In this study, the F gene of NDV/Chicken/XJ/3/07 strain, NDV/Chicken/XJ/7/07 strain, NDV/Chicken/ XJ/9/08 strain, NDV/Chicken/XJ/10/08 strain and NDV/Pigeon/XJ/11/08 strain were amplified by RT-PCR and cloned. The sequence analysis showed that the full-length gene of F were 1 662bp, 1 589bp, 1 662bp, 1 586bp and 1 676bp, coded for 553, 528, 553, 520 and 553 amino acids respectively. According to the analysis of amino acid sequence of the cleavage site of F protein, the NDV/Chicken/XJ/10/08 strain was virulent and the others NDV strains were avirulent. The phylogenetic analysis suggested that the NDV/C -hicken/XJ/3/07 strain, NDV/Chicken/XJ/7/07 strain, NDV/Chicken/XJ/9/08 strain and NDV/Pigeon/XJ/ 11/08 strain were gene typeâ…¡, and the XJ/10/08 strain was gene typeâ…¦.In this study, the HN gene of NDV/Chicken/XJ/9/08 strain, NDV/Chicken/XJ/10/08 strain and NDV/ Chicken/XJ/17/08 strain were amplified by RT-PCR and cloned. The sequences analysis showed that the full-length of HN gene were 1 734bp, 1 716bp and 1 716bp, coded for 577, 571 and 571 amino acids respectively. The nucleotide sequence alignment analysis for NDV/Chicken/XJ/9/08 strain revealed that there were mutations in the sites of 12, 188, 377, 459, 1 067 and 1 390. Compared NDV/Chicken/XJ/10/08 strain and NDV/Chicken/XJ/17/08 strain with Tanwan95 showed that there were mutations in the sites of 227-560 and 1 120-1 141. The analysis of peptide length of HN gene showed that the NDV XJ/9/08 strain was avirulent and the NDV/Chicken/XJ/10/08 strain and NDV/Chicken/XJ/17/08 strain were virulent. The genetic evolution analysis suggested that NDV/XJ/9/08 strain and vaccine strains were in the same branch. They have far relationship with the other two Xinjiang strains. NDV/Chicken/XJ/10/08 strain and NDV/C- hicken/XJ/17/08 strain close to Jiangsu strain, Guangxi strain, Zhejiang strain and Taiwan95, the two strains have far relationship with vaccine strains.The analysis for the HN gene demonstrated that the NDV/XJ/9/08 strain was avirulent and NDV/Chi- cken/XJ/10/08 strain and NDV/Chicken/XJ/17/08 strain were virulent. The results were consistent with F gene. Although NDV/Chicken/XJ/3/07 strain, NDV/Chicken/XJ/7/07 strain, NDV/Chicken/XJ/9/08 strain and NDV/Pigeon/XJ/11/08 strain were avirulent, there were mutations in some sites of nucleotide sequences. The gene mutations caused that ND was infected in the immune chickens. It is necessary to strengthen the immune monitoring and program the rational schedule of immunization. |
