Frameshift is relevant to both plant and mammalian viruses, including Human Immunodeficiency Virus Type 1 (HIV-1) and Human Coronavirus (HCV). This frameshift allows for the translation of the RNA dependent RNA polymerase (Rd-RP). BYDV is a well-characterized plant virus with several unique translational processes, including a long distance base pairing which allows -1 frameshift. Nucleotides on the bulge of the adjacent downstream stem loop (ADSL) base pair to the long distance frameshift element (LDFE), four kilobases downstream. This novel mechanism requires further characterization since other cis acting components both distal and proximal to the frameshift site were found to influence frameshift. These regions will be assessed through structural analysis, site directed mutagenesis and in vitro and in vivo frameshift assays within wheat and oat protoplast transfection systems to quantitatively measure frameshift efficiencies. These assays will delineate the responsible RNA domains, necessary for frameshift.