Production and Verification of Drosophila melanogaster Nora virus Monospecific Antisera. Morgan Caron Abert, Brad L. Ericson, Darby J. Carlson, Kimberly A. Carlson. Biology, University of Nebraska at Kearney, Kearney, NE.

   Nora virus is a picorna-like virus that has four open reading frames (ORFs), as opposed to the one long ORF found in most members of this group. The coding potentials of the ORFS are not fully characterized, but ORF1, ORF3, and ORF4 are believed to code capsid proteins. There are three viral proteins identified in ORF4 that are of interest, VP4A, VP4B, and VP4C. The purpose of this study was to produce monospecific antisera to purified whole Nora virus and purified recombinant VP4B, and to evaluate the specificity of both via Western blot analysis. Nora virus was purified from infected Drosophila melanogaster on CsCl gradients and His-tagged recombinant Nora virus VP4B protein was purified on Ni⁺² columns. Both whole virus and VP4B were injected into mice to make polyclonal antibodies. The resulting monospecific antisera were evaluated in Western Blot assays. The results showed that a majority of the predicted Nora virus structural proteins were detected using whole virus antiserum. Monospecific antiserum against VP4B detected two proteins in purified virus. The production and validation of monospecific antisera is a useful tool to investigate other aspects of Nora virus such as replication sites in host flies and the location of the various structural proteins in the virion. This work was partially made possible by Grant Number P20GM103427 from the National Institute for General Medical Science, a component of the National Institutes of Health.