title: Systematic CpT (ApG) depletion and CpG excess are unique genomic signatures of large DNA viruses infecting invertebrates.
abstract: Differences in the relative abundance of dinucleotides, if any may provide important clues on host-driven evolution of viruses. We studied dinucleotide frequencies of large DNA viruses infecting vertebrates (n = 105; viruses infecting mammals = 99; viruses infecting aves = 6; viruses infecting reptiles = 1) and invertebrates (n = 88; viruses infecting insects = 84; viruses infecting crustaceans = 4). We have identified systematic depletion of CpT(ApG) dinucleotides and over-representation of CpG dinucleotides as the unique genomic signature of large DNA viruses infecting invertebrates. Detailed investigation of this unique genomic signature suggests the existence of invertebrate host-induced pressures specifically targeting CpT(ApG) and CpG dinucleotides. The depletion of CpT dinucleotides among large DNA viruses infecting invertebrates is at least in part, explained by non-canonical DNA methylation by the infected host. Our findings highlight the role of invertebrate host-related factors in shaping virus evolution and they also provide the necessary framework for future studies on evolution, epigenetics and molecular biology of viruses infecting this group of hosts.
authors.affiliation: Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India.
authors.forename: Mohita
authors.initials: M
authors.lastname: Upadhyay
authors.affiliation: Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India.
authors.forename: Neha
authors.initials: N
authors.lastname: Sharma
authors.affiliation: Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India.
authors.forename: Perumal
authors.initials: P
authors.lastname: Vivekanandan
mesh_terms: D001482:Base Composition; D003062:Codon; D018899:CpG Islands; D019175:DNA Methylation; D004267:DNA Viruses / Q000235:genetics*; D004279:DNA, Viral / Q000235:genetics*; D005814:Genes, Viral; D058507:Host Specificity; D054884:Host-Pathogen Interactions; D017422:Sequence Analysis, DNA
chemical_list: D003062:Codon; D004279:DNA, Viral