Construction Of Universal Transfer Vector Marek's Disease Virus Vaccine Strain CVI988/Rispens And Development Of Recombinant MDV Expressing The VP2 Gene Of Infectious Bursal Disease Virus

Marek's disease (MD) is one of acute viral disease of commercial poultry worldwide and controlled by immunization. The field experience has clearly demonstrated the safety and effectiveness of the MDV vaccines as a viral vector. Infectious bursal disease (IBD) is an acute, highly contagious viral infection of chickens and turkeys. Conventional vaccines especially middle virulence vaccine is the main method of controlling IBD. However vaccine caused the immune suppression, making resistance prone to other diseases as well as raising the effectiveness of other vaccines. So we used CVI988/Rispens vaccine strain as a vector, IBDV-VP2 as a protective antigen gene to construct the rMDV, laid the foundation for the further study of recombinant MDV vaccine.1 Construction of universal transfer vector marek's disease virus vaccine strain CVI988/RispensThe US10 and its blanks, US1 and sorf, of CVI988/Rispens strain were amplified by PCR using primers synthesized according to the nucleotide sequence of the"virulent"GA strain of MDV I published in GenBank and cloned into pGEM-T-easy the vector to obtain plasmid T-US10L,T-US10R. By sequencing, the cloned genes presented absolutely uniform appearances to those of very virulent GA strains of MDV I. Then the US10R was inserted into the vector pUC18 to obtain the plasmid pUC18-US10R, and the US10L was inserted into the plasmid pUC18-US10R subsequently to get the...