Cloning And Sequences Analysis Of N Gene And G Gene Of Wild Rabies Virus Strains Isolated In Guangxi

In this study three wild strains of rabies virus were isolated from Nanning, Longan and Bama of Guangxi and were designated as 119, GXLA and GXBM respectively. The nucleoprotein(N) gene of three strains and glycoprotein(G) gene of 119, GXBM were amplified by reverse transcription-polymerase chain reaction(RT-PCR), respectively. The RT-PCR products were cloned into pMD18-T vector and then sequenced. The sequences of N and G gene and their deduced amino acid sequences were compared and analyzed with that of some other rabies virus strains published previously in the world. The nucleotide homology in N gene among three street strains were 89.1%(119/GXBM) ,89.7%(119/GXLA) and 89.4% (GXLA/GXBM) and in G gene among two street strains were 86.7% (119/GXBM) ,which were different and obviously low. These results suggested that genetic relationship in three strains isolated from different place of Guangxi is rather distant. The homology of deduced amino acid sequence of N gene among the three strains are 97.8%(119/GXBM) ,97.8%(119/GXLA) and 99.1% (GXLA/GXBM) respectively.The result demonstrated that there were many synonymous mutations in N gene.Comparison of the sequence of nucleotide and deduced amino acid of G gene of 119 and GXBM with that of 3aG and ERA vaccine strains, the homologies of nucleotide were ranged from 82.7% to 84.0% and 88.0% to 91.6%, homologies of amino acid has been showed 91.0%, 88.8%, 90.5% and 88.0% , respectively. However ,the homologies of G and N gene between wild strains and attenuated strain CTN are much high.According to the deduced amino acid of G gene , there are two glycosylation sites in strain 119 and GXBM at position 37 and 319.There is few change in important neutralizing antigenic epitope and in some antigenic sites related with pathogenicity.The results in this experiment are very important for further study on development of genetic engineering vaccine against rabies and on the investigation of molecular epidemiology of rabies virus.