Cloning,Sequencing Of N Gene Of Strain M Of Rabies Virus Isolated From Mouse

Rabies is a zoonotic viral disease whose presence has been noted throughout recorded history. Rabies in inevitably fatal by the time that significant symptoms appear, which is why prophylaxis must be started before symptoms appear. It causes a highly fatal acute encephalitis, causing approximately 35,000~50 000deaths each year worldwide. Rabies virus belongs to the Rhabdoviridae family.The N protein of rabies virus is responsible for encapsulation of viral RNAs,and the L protein, in cooperation with the P protein, functions as an RNA-dependent RNA polymerase.And N protein alone can induce protective immunity against lethal infection in animals.Furthemore,the homology of nucleoprotein genes derived from different rabies virus strains is rather conservative.As a result,it is widely used the molecular epidemiology in the world.diagnostic reagent and genetic vaccine.The purpose of cloning and sequence analysis of nucleoprotein genes of rabies virus M Strain is identifying its genotype and researching efficient genetic vaccine.Based on published gene sequence data,a pair of primers specific for NP gene was designed.The N genes(about 1400nt)of strain M.isolated from mouse,rangigng from 70nt to 1499nt was amplified by reverse transcription-polymerize chain reaction(RT-PCR),then cloned into PGEM-T vector and sequenced by biology company. Comparison and analysis of the nucleotide sequence and amino acid sequence deduced with that 9 strains previously published were performed by computer with DNAStar software. Results showed that the cloned some 1400bp fragment covered the open reading frame encoding 451 amino acids of the NP gene, The NP gene sequence of the M strain isolate was highly homologous to that of CVS .And they have the same Antigenic site. But, T377 was changed into S377 at AgI site of CVS and MRV.Q79 was changed into E79 at AgII site of 8202.T90 was changed into N90 at AgII site of CTN.It is possible that the only acid changed will affectthe secondary structure N protein. Phylogenitic trees were established. The nucleotide and amino acid homology of MRV with CVS were 99.0% and 99.6% respectively. The homology with other strains was also more than 92.0%. It proved that all of strains including MRV strain were genotype I and Strains M and CVS were divided into sub-genotypes.