U exon variability as a discriminatory tool for Bayesian analysis of adenoviruses

Members of the family Adenoviridae are divided into five genera and infect a wide variety of vertebrates with a narrow host range, usually restricted to one species. Due to the high genetic diversity and distinct genomic organization, classification of adenoviruses is difficult to achieve and often performed by phylogenetic analysis. The most commonly used region for phylogenetic inference of adenoviruses is the DNA polymerase (AdPol) gene carried out at amino acid level. In this paper we investigated the suitability of the U exon to discriminate adenoviruses. The tree based on this genus-common feature, obtained with 23 short amino acid sequences, offered a clearest discrimination of the members of the adenovirus family (Adenoviridae) than the trees generated with the complete or partial polymerase protein sequences. Therefore, our results demonstrate that the U exon is an effective tool for a refined phylogenetic inference and genus classification of the Adenoviridae family.