title: A Role for the Anti-Viral Host Defense Mechanism in the Phylogenetic Divergence in Baculovirus Evolution.
abstract: Although phylogenic analysis often suggests co-evolutionary relationships between viruses and host organisms, few examples have been reported at the microevolutionary level. Here, we show a possible example in which a species-specific anti-viral response may drive phylogenic divergence in insect virus evolution. Two baculoviruses, Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and Bombyx mori nucleopolyhedrovirus (BmNPV), have a high degree of DNA sequence similarity, but exhibit non-overlapping host specificity. In our study of their host-range determination, we found that BmNPV replication in B. mori cells was prevented by AcMNPV-P143 (AcP143), but not BmNPV-P143 (BmP143) or a hybrid P143 protein from a host-range expanded phenotype. This suggests that AcMNPV resistance in B. mori cells depends on AcP143 recognition and that BmNPV uses BmP143 to escapes this recognition. Based on these data, we propose an insect-baculovirus co-evolution scenario in which an ancestor of silkworms exploited an AcMNPV-resistant mechanism; AcMNPV counteracted this resistance via P143 mutations, resulting in the birth of BmNPV.
authors.affiliation: RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Nagamine
authors.affiliation: RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sako
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D012831:Bombyx / Q000821:virology; D004279:DNA, Viral / Q000235:genetics; D019143:Evolution, Molecular; D005814:Genes, Viral; D058507:Host Specificity / Q000235:genetics; D054884:Host-Pathogen Interactions / Q000235:genetics; D008957:Models, Genetic; D009154:Mutation; D017924:Nucleopolyhedroviruses / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D010802:Phylogeny; D014764:Viral Proteins / Q000235:genetics; D014779:Virus Replication / Q000235:genetics
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins