title: Passage of a Sendai virus recombinant in embryonated chicken eggs leads to markedly rapid accumulation of U-to-C transitions in a limited region of the viral genome.
abstract: The P gene of paramyxoviruses is unique in producing not only P but also "accessory" C and/or V proteins. Successful generation of C- or V-deficient recombinant viruses using a reverse genetics technique has been revealing their importance in viral pathogenesis as well as replication. As for Sendai virus (SeV), the C proteins, a nested set of four polypeptides C', C, Y1, and Y2, have been shown to exert multiple functions in escaping from the host innate immunity, inhibiting virus-induced apoptosis, promoting virus assembly and budding, and regulating viral RNA synthesis. In this study, we subjected the 4C(-) recombinant lacking expression of all four C proteins to serial passages through eggs, and found the rapid emergence of a C-recovered revertant virus. Unlike the SeV strains or the recombinants reported previously or tested in this study, this was caused by an exceptionally quick accumulation of U-to-C transitions in a limited region of the 4C(-) genome causing recovery of the C protein expression. These results suggest that a lack of C proteins could lead unexpectedly to strong selective pressures, and that the C proteins might play more critical roles in SeV replication than ever reported.
authors.affiliation: Department of Virology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Asuka
authors.initials: A
authors.lastname: Yoshida
authors.forename: Takemasa
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Irie
mesh_terms: D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D003596:Cytosine / Q000737:chemistry; D016679:Genome, Viral; D008253:Macaca mulatta; D012367:RNA, Viral / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D011995:Recombination, Genetic; D029082:Sendai virus / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity; D014498:Uracil / Q000737:chemistry; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
chemical_list: D012367:RNA, Viral; C111739:V protein, Sendai virus; D014764:Viral Proteins; C051221:nonstructural C protein, Sendai virus; D014498:Uracil; D003596:Cytosine