title: Mapping genetic determinants of the cell-culture growth phenotype of enterovirus 71.
abstract: Enterovirus 71 (EV71) is a member of the species Human enterovirus A within the family Picornaviridae and is a major causative agent of epidemics of hand, foot and mouth disease associated with severe neurological disease. Three EV71 genogroups, designated A, B and C, have been identified, with 75-84 % nucleotide sequence similarity between them. Two strains, EV71-26M (genogroup B) and EV71-6F (genogroup C), were found to have distinct cell-culture growth (26M, rapid; 6F, slow) and plaque-formation (26M, large; 6F, small) phenotypes. To identify the genome regions responsible for the growth phenotypes of the two strains, a series of chimeric viruses was constructed by exchanging the 5' untranslated region (UTR), P1 structural protein or P2/P3 non-structural protein gene regions plus the 3'UTR using infectious cDNA clones of both virus strains. Analysis of reciprocal virus chimeras revealed that the 5'UTRs of both strains were compatible, but not responsible for the observed phenotypes. Introduction of the EV71-6F P1 region into the EV71-26M clone resulted in a small-plaque and slow-growth phenotype similar to that of EV71-6F, whereas the reciprocal chimera displayed intermediate-growth and intermediate-sized plaque phenotypes. Introduction of the EV71-26M P2-P3-3'UTR regions into the EV71-6F clone resulted in a large-plaque and rapid-growth phenotype identical to that of strain EV71-26M, whereas the reciprocal chimera retained the background strain large-plaque phenotype. These results indicate that, although both the P1 and P2-P3-3'UTR genome regions influence the EV71 growth phenotype in cell culture, phenotype expression is dependent on specific genome-segment combinations and is not reciprocal.
authors.affiliation: Discipline of Infectious Diseases and Immunology, The University of Sydney, Sydney, Australia.
authors.forename: Patchara
authors.initials: P
authors.lastname: Phuektes
authors.affiliation: School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Perth, Australia.
authors.forename: Beng Hooi
authors.initials: BH
authors.lastname: Chua
authors.affiliation: School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Perth, Australia.
authors.forename: Sharon
authors.initials: S
authors.lastname: Sanders
authors.affiliation: Discipline of Infectious Diseases and Immunology, The University of Sydney, Sydney, Australia.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Bek
authors.affiliation: Discipline of Infectious Diseases and Immunology, The University of Sydney, Sydney, Australia.
authors.forename: Chee Choy
authors.initials: CC
authors.lastname: Kok
authors.affiliation: Discipline of Infectious Diseases and Immunology, The University of Sydney, Sydney, Australia.
authors.forename: Peter C
authors.initials: PC
authors.lastname: McMinn
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D002874:Chromosome Mapping; D029821:Enterovirus A, Human / Q000145:classification / Q000235:genetics* / Q000254:growth & development* / Q000302:isolation & purification; D006232:Hand, Foot and Mouth Disease / Q000821:virology*; D006801:Humans; D008969:Molecular Sequence Data; D020506:Untranslated Regions; D014709:Vero Cells; D014776:Virus Cultivation
chemical_list: D020506:Untranslated Regions