Selective Factors Associated with the Evolution of Codon Usage in Natural Populations of Arboviruses

PLoS One. 2016 Jul 25;11(7):e0159943. doi: 10.1371/journal.pone.0159943. eCollection 2016.

Abstract

Arboviruses (arthropod borne viruses) have life cycles that include both vertebrate and invertebrate hosts with substantial differences in vector and host specificity between different viruses. Most arboviruses utilize RNA for their genetic material and are completely dependent on host tRNAs for their translation, suggesting that virus codon usage could be a target for selection. In the current study we analyzed the relative synonymous codon usage (RSCU) patterns of 26 arboviruses together with 25 vectors and hosts, including 8 vertebrates and 17 invertebrates. We used hierarchical cluster analysis (HCA) and principal component analysis (PCA) to identify trends in codon usage. HCA demonstrated that the RSCU of arboviruses reflects that of their natural hosts, but not that of dead-end hosts. Of the two major components identified by PCA, the first accounted for 62.1% of the total variance, and among the 59 codons analyzed in this study, the leucine codon CTG had the highest correlation with the first principal component, however isoleucine had the highest correlation during amino acid analysis. Nucleotide and dinucleotide composition were the variables that explained most of the total codon usage variance. The results suggest that the main factors driving the evolution of codon usage in arboviruses is based on the nucleotide and dinucleotide composition present in the host. Comparing codon usage of arboviruses and potential vector hosts can help identifying potential vectors for emerging arboviruses.

MeSH terms

  • Amino Acids
  • Arbovirus Infections / virology
  • Arboviruses / genetics*
  • Base Composition
  • Biomarkers
  • Cluster Analysis
  • Codon*
  • Evolution, Molecular*
  • Genome, Viral
  • Genomics / methods
  • Host-Pathogen Interactions
  • Selection, Genetic*
  • Viral Proteins / chemistry
  • Viral Proteins / genetics
  • Viral Tropism

Substances

  • Amino Acids
  • Biomarkers
  • Codon
  • Viral Proteins

Grants and funding

The authors have no support or funding to report.