Study On Production Of Monoclonal Antibodies To Newcastle Disease Virus And Analysis Of Heredity And Variation Of NDV

Study on Production of Monoclonal Antibodies to Newcastle Disease Virus and Analysis of heredity and Variation of NDV Qu Lujiang(College of Animal Husbandry, Xinjiang Agricultural University, Uruiitqi 830052 Supervised by Prof. Shan lVenlu&Ass. Prof. Cao Dianjun Abstract The paper included two parts. The destiny of the former was to get the monoclonal antibodies (McAbs) to Newcastle Disease Virus(NDV) that would be used to analyze heredity and variation of NDV In the second part, through cloning., sequencing and analyzing F gene of two NDV isolates, we found the status of the two isolates in phylogenetic tree. Through immuning BALB/C mouse with antigen that is virulent NDV F4~E9 strain purified by method of sucrose density centrifuge, cellular fusion, clone and detection, we obtained six strains of hybridoma cells that could produce McAbs-five to RN protein and one to F protein. The ELISA titer of all ascites of McAbs are more than iiiO3 . McAbs to uN protein have high HI titer and the McAb to F protein can neutralize NDV and has high PFU. Cellular ELISA was proved to be an economic and effective way to detect different NDV isolates. Two strains of NDV isolated from outbreaks in 1997 and 1999 in Jiangxi and Yunnan, which were named as FJJ and FYi, were cloned by plaque and characterized by hamagglutination profile, mean death time(MDT) in embryos and intracerebral pathogenicity index(ICPI). Selected isolates received further characterization by portions of the fusion protein(positions 1-389). The MIDT values and ICPI values of the two isolates were high, which indicated all isolates were velogenic. By reverse transcription polymerase chain 4 reaction, the products of part F gene from NDV isolates were obtained and cloned in PUCI 19, then position 1-519 were sequenced. Following alignment of nucleotide sequence genetic relationships among isolates were revealed. Although overall homology was remarkably high, the sequence variability demonstrated the existence of evolution. The most significant within F protein is concerned the region bordering the Fl/F2 cleavage site. All virulent strains of NDV have the amino acid 112RRQR(K)RF?7 at cleavage site, while all avirulent strains have ?2GRQG(K)RL?7. The isolates in this study have a similar cleavage site to virulent strains. Based on sequence analysis of the first 389bp nucleotides of the coding region of F-gene, a phylogenetic tree of NDV strains was constructed. All N7DV strains circulated from 1940抯 to now were divided into nine genotypes. One strain in this study belonged to group VII, and the other belonged to group VIII, which was a novel genotype of NDV in China.