الفهرس | Only 14 pages are availabe for public view |
Abstract The nucleocapsid (N) protein and the two subunits of spike protein (S1 and S2) of bovine coronavirus (BCV) , Mebus strain , were individually expressed in Spodopetra frugiperda (Sf9) insect cells using recombinant baculovirus vectorsBCV was propagated in MDBK cells for 4 successive passages , titrated and characterized by plate haemagglutination and direct immuno - fluorescent testsThe viral RNA was extracted from infected cells and the coding sequence of each BCV target gene was amplified using RT - PCRThe RT - PCR products were cloned into the baculovirus shuttle vector ; pBlueBac45 / V5 - His TOPO and the recombinant plasmids that carry target genes in correct orientation were identifiedThe cloned genes were introduced in the genome of Autographa californica nuclear polyhydrosis virus (AcMNPV) under control of the polyhedrin promoter , through a process of homologous recombination between the shuttle vector and a linearized replication - defective baculovirus DNA (Bac - N - Blue\{u2122\}) Recombinant baculoviruses were selected by plaque purification ; verified for the presence of target genes using PCR and propagated for generation of high - titer viral stockInfection of insect cells with the recombinant baculoviruses revealed high - level expression of the target proteins as indicated by immunofluoresent test and solid phase ELISA using BCV - specific polyclonal antiserumWhile Western blot assay was appropriate for detection of the expressed N protein under both reducing and non - reducing conditions , S1 and S2 polypeptides were not recognized in both conditions. |