Characterization of the genes encoding complete US10, SORF3, and US2 proteins from duck enteritis virus.

Based on the understanding that the analysis on unique short (US) region of duck enteritis virus (DEV) might contribute to the recognition of the molecular characterization and the evolution of DEV, in the study, a 5,121 bp fragment, which contained three genes encoding complete US10, unique short region open reading frame (SORF) 3, and US2 proteins, was amplified from the DEV (C-KCE) genome. The transcription orientation of the US10 and SORF3 was in a tail-to-tail way, and the SORF3 and US2 was the same. Potential core promoters and polyadenylation (poly(A)) sites were predicted for US10, SORF3, and US2 and further confirmed by polymerase chain reaction. Phylogenetic analysis for the three complete coding sequences showed that DEV was more closely related to avian herpesviruses, especially to Mardivirus, and should be classified to a separate genus of the Alphaherpesvirinae subfamily.