Characterisation of the Equine adenovirus 2 genome.

This research article presents the complete genome sequence of Equine adenovirus 2 (EAdV-2), a virus known to infect equines, and examines its linkage with clinical and subclinical gastrointestinal infections in foals and horses. The study also makes observations on the virus’s evolutionary history and its distinction from a different serotype, Equine adenovirus 1 (EAdV-1).

Exploration of EAdV-2’s Genomic Profile

• The researchers performed a comprehensive analysis of the EAdV-2 genome, using various bioinformatics techniques.
• They identified genes that are common to adenoviruses, showing the presence of shared genetic markers.

Phylogenetic Reconstruction

• The team used selected EAdV-2 genes to conduct phylogenetic reconstructions. These reconstructions rightly asserted the virus’s place within the Mastadenovirus genus.
• Moreover, the study reinforced the notion that EAdV-2 and EAdV-1 have evolved from separate adenovirus lineages, conveying their distinct evolutionary paths.

Identification of Coding Sequences and Polypeptides

• A spliced open reading frame (ORF) that encodes for a polypeptide was detected. This polypeptide bore a high similarity to the pIX and E1b_55K adenovirus homologues and was named pIX_E1b_55K as per these findings.
• Apart from this fused version of E1b_55K, a separate gene encoding E1b_55K was also found.
• These polypeptides were not found to have evolved from a gene duplication event. The fused E1b_55K and the unfused E1b_55K shared their highest similarity with E1b_55K homologues from the Atadenovirus and Mastadenovirus genera respectively.

Intriguing Evolutionary History

• The findings in the EAdV-2 genome suggest an unusual evolutionary history for this particular virus. Moreover, the distinct coding sequences and the independence from gene duplication events also hint at a unique genomic composition.
• This rarity in evolutionary mechanism calls for further probes in order to assess its overall viral architecture, modus operandi and any adaptive processes that might be working on it.