Translational adaptation of human viruses to the tissues they infect

Xavier Hernandez-Alias; Martin Schaefer; Luis Serrano

While previous studies on the base composition and codon usage of both DNA and RNA viruses 11, 30 have attributed most of the codon usage variability to the mutational pressure of viral genomes, our analysis proposes tropism as an important driving force. By systematically interrogating all human-infecting viruses, we uncover that tissue tropism explains changes in their codon usage more than other viral properties such as type or family. Therefore, as mutational pressure would act more similarly within phylogenetically closer species, such tropism-related differences in codon usage suggests that tissue-specific tRNA expression could be driving a translational selection on viral genomes.