Cloning And Sequence Analysis Of NP, P And M Gene Of NDV Strain Changchun And Study On Immunogenicity Of HN Recombinant Protein

A NDV strain which was named Changchun was isolated and identified. Biological characters research shows that it can agglutinate chicken and human erythrocytes but can not agglutinate the erythocytes of swine, sheep, goat, cow and horse. The results of mean death time(MDT) of chicken embryo and intracerebral pathogenicity index(ICPI) of 1-day-old chicken and intravenous pathogenicity index(IVPI) of 6-week-old chicken showed that it was an avirulent strain(MDT>168h, ICPI=0.25, IVPI=0).Three pairs of specific oligonucleotide primers for amplifying the NP, P and M gene of NDV were designed according to the published relevant sequences of NDV, and then the NP, P and M gene of the Changchun strain were amplified by RT-PCR, and sequenced subsequently. The ORF of the NP, P and M gene is consist of 1470bp,1188bp and 1095bp respectively. Compared NP, P and M gene of strain Changchun with the published NDV strains (i. g. La sota, Bl et al.), the homology of the nucleotide sequence is 85.7%-99.1%,82.8%-96.9% and 84.3%-99.7%,and the homology of the deduced amino acids sequence is 92.5%-99.3%, 84.3%-95.9%, 88.9%-99.1% .Antigen A and B were prepared by mixing complete Freund's adjuvant and incomplete Freund's adjuvant respectively with recombinant HN protein of NDV strain Changchun. After chicken were immunized twice using antigen A and B with intramuscular route, antibody was determined by ELISA and HI test. The result showed primarily that recombinant protein can induced chickens to produce special anti-NDV HN protein antibody and anti-HN protein HI antibody and the chicken were able to resist the challenge of NDV virulent strain F48E8.