are characterized as 107-bp on 5’ side and 157-bp on 3’ end. The start codons can be at either position 102, or two codons downstream at position 108. However, the initiation codon starts at the 108-bp. The translation of the large ORF transcript produces a 114-kDa polyprotein. The mature VP4 protein, viral protease, assists this process to increase the processing of the polyprotein to generate preVP2 capsid protein, VP3 viral ribonucleoprotein (RNP), and additional VP4 proteins. In addition VP3 proteins can associate with pre-VP2 as a structural protein and with VP1 to function as a transcriptional activator. The small ORF of segment A consists of 711 nucleotides. This ORF is in a location that extends across VP4/VP3 junction, although the precise position is unknown. The mechanism for transcribing the small ORF is unknown. However, the possibility of ribosomal frameshifting has been ruled out since the small ORF site does not contain the characteristic hallmarks, such the 7 nucleotide long “slippery sequence” or downstream pseudoknot that is seen in other members of Birnaviridae. It is hypothesized the small ORF is translated in a mechanism that uses subgenomic transcripts. In any case, the translation of the small ORF transcript produces a 27-kDa polypeptide. This polypeptide consists of 28 of basic, mainly arginine, residues. However this polypeptide has not been detected in infected cells. The segment B transcript encodes it encodes a 112.8-kDa VP1 polypeptide once translated. This polypeptide has been characterized to be the RNA-dependent RNA polymerase (RdRp) and the VpG. This polypeptide is 977 amino acids in length, making it the largest encoded RdRp in the Birnaviridae family. The RdRp contains a consensus GTP-binding site and is thought to contain self-guanylylation activity, making it consistent with the Birnaviridae RdRp capacity. Tropism Currently, DXV does not infect vertebrates. It is known that invertebrates, such as insects, are hosts for DXV, but their specific tissue tropism is not known for certain. Tracheal cells were thought to be a possible target because there is evidence that Drosophila flies that are infected by DXV suffered from lack of oxygen supply to their tissues, which eventually leads to death. Based on previous studies, DXV was unsuccessfully cultured in vertebrate cells lines and mouse brain. Genetic variability It has not been shown yet that DXV naturally infects Drosophila flies therefore; there are no wild-type strains of DXV. The Culex Y virus (CYV) is a tentative member of