Vidhya, MJohn Kirubaharan, JRajalakshmi, SRajasekaran, RanjiniTANUVAS2020-03-052020-03-052020-02http://krishikosh.egranth.ac.in/handle/1/5810144282TNV_20thMVC_PP_Feb-2020_OP48The Nuclepcapsid protein (N) protein of Newcastle disease virus (NDV), synonymous with Avian Avula virus-1(AAv-1) functions primarily to encapsidate the virus genome for transcription, replication and packaging. In addition to its role in replication, N gene is the major immunogenic and conserved gene of NDV. Identifying mutation permissive regions in the N protein provides a potential approach for NDV marker vaccine. In the present study mutations introduced in to the NP gene in the form of epitope replacement between amino acid positions 446-453 was analysed using an intracellular NDVD58-GFP minigenome assay for its effect on minigenome RNA synthesis and encapsidation.Site directed mutagenesis was carried out in pCIneo N plasmid to replace the NDV epitope 446(QFLDLMRAV)453 with a marker epitope TAVSPTTLR.The mutated pCIneo N plasmid was co-transfected with other NDV expression plasmids pCIneo L, pCIneo P and pNDVD58-GFP minigenome plasmid in BSR/T7 cells. GFP expression was observed 72 hours post transfection indicating a functional minigenome. Further the presence of encapsidated minigenome RNA in transfected cell supernatants were also confirmed by Real time PCR. These results indicate that the mutations did not affect the functionality of the Nucleoprotein and can serve as marker epitopes for NP based ND marker vaccine.enVeterinary SciencePresentation