Characterization of Codon Usage Bias in UL13 Gene of the Duck Plague Virus

Abstract

A comprehensive analysis of codon usage bias of DPV UL13 gene (GenBank Accession No. EU195098) was performed to provide a basis for understanding the relevant mechanism for its biased usage of synonymous codons and for selecting suitable expression systems to improve the expression of UL13 genes. Our study showed that codon usage bias of DPV UL13 gene strongly prefered to the synonymous with A and T at the third codon position. And ENC value and GC3s contents of the codon usage bias of UL13 gene in DPV were significantly different compared with those in other 21 reference herpesviruses. The phylogentic analysis about the putative protein of DPV UL13 and the 21 reference herpesviruses revealed that DPV was evolutionarily closer to the AnHV-1. In addition, the codon usage bias of DPV UL13 gene was compared with those of E. coli, yeast and human. There are 23 codons showing distinct usage differences between DPV and E. coli, 12 codons between DPV and yeast, 21 codons between DPV and human. Therefore, the yeast expression system is more appropriate for heterologous expression of the DPV UL13 gene.