Molecular Cloning and Characterization of the UL10 Gene from Duck Enteritis Virus

We determined the nucleotide sequence of a portion of the duck enteritis virus (DEV) strain CHv which was suspected to be the UL10 gene(GenBank accession no EU195100.), encoding glycoprotein M(gM). The UL10 gene was cloned and sequenced, which was composed of 1230 nucleotides encoding 409 amino acids, with a predicted molecular mass of 45.752 kDa. We calculated the codon usage bias in the newly identified UL10 gene of Duck Enteritis Virus (DEV) and performed a correlation analysis of codon bias of DEV UL10 gene. There is a strong bias in the DEV UL10 gene towards the synonymous codons with A and T at the third codon position. Multiple sequence alignment suggested that the UL10 gene was highly conserved in Alphaherpesvirinae and similar to the other herpesviral UL10. Phylogenetic analysis showed that the gene had a close evolutionary relationship with the avian herperviruses, and DEV should be placed into a single cluster within the subfamily Alphaherpesvirinae. Furthermore, the UL10Δ gene was cloned into a pET prokaryotic expression vector and transformed into Escherichia coli BL21 (DE3). A 6 kDa fusion protein was induced by the further culture at 30°C after addition of 0.8mM IPTG. Our results may provide some insight for further research about the gene and also enrich the database of herpesvirus.