Studies On Genetic Variation Of VP1 Genes Of Asia â…  FMDV Inactivated Vaccine Strains From Serial Passages In Different Hosts

Foot and mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. It breaks out almost every year all over the world, and it can cause huge economical loss. FMDV has the same high mutation rates as others RNA viruses. Analysis of genetic variation during the passage is indispensable for vaccine research. The VP1 gene is the main antigenic epitopes of FMDV which plays very important roles in inducing neutralization antibodies and other immune protection.The mutation rate of VP1 gene's nucleotide is the most highest in four structural protein. The study of VP1 gene is beneficial for not only the study of genetic variation stability of inactivated vaccine strains but also the study of epidemiology, the global tracing of virus movements and development of new vaccine.It shows a substantial upward trend of FMDV Asiaâ… in recent years in China and Asia, and the vaccine of FMD type O can not control current epidemic. It is very urgent to develop O- Asiaâ… FMDV Bivalent inactivated vaccine to control FMD.The paper was studied on the sequence analysis of nucleotide and the deduced amino acid of VP1 gene of inactivated vaccine strains, which was isolated from Ke Zhou of Xinjiang and was generated in different hosts such as suckling mouse and cell of BHK21, named MF1, MF5, MF7, CF3, CF10, CF15. In order to proof the genetic stability of this strain.we used DNAstar software to study the variation of nucleotide sequences of VP1 gene, and compared them with current epidemical strains. This work provided the scientific basis for the passage base identified of the virus of suckling mouse and cell culture in the process of developing vaccine.The result demonstrate that the length of six strains VP1 gene was 633bp which is encoded 211 amino acids.The homologies among VP1 gene sequences are 99.4-99.8%,and the homologies among the deduced amino acid sequences are 98.6%-100%. Compared with the MF1, insert and deletion are not found in the nucleotide.The high variation region of amino acids and the main antigenic sites,such as RGD region,G-H loop, T-cell and B-cell epitopes , Sau3Aâ… restriction enzyme sites are all conserved. So it is stable for producing inactivated vaccine and suitable to related livestock in prevailed area for immune prevention.