title: Comparative sequence analysis of A-type inclusion (ATI) and P4c  proteins of orthopoxviruses that produce typical and atypical ATI  phenotypes.
abstract: Some orthopoxviruses produce large proteinaceous intracellular bodies, known as A-type inclusions (ATIs) during infection of host cells. Virions associate with ATIs resulting in distinct phenotypes referred to as V+, V+/ and V⁻. The phenotype V+ has the virions embedded in the ATI matrix; V⁻ has no virions embedded within or on the surface of the ATI matrix, whereas an aberrant phenotype, the V+/ has virions only on the surface of ATIs. Viruses that do not produce ATI are designated as V⁰. Recombinant viruses generated from a V+ cowpox virus (CPXV) and a V⁰ transgenic vaccinia virus (VACV) produced aberrant V+/ ATIs. ATI phenotype is dependent on the A-type inclusion protein (Atip) and the P4c protein. We sequenced the atip and p4c genes of parental and progeny recombinant viruses as well as their flanking sequences. The atip and p4c open reading frames were identical in parental V+ CPXV and hybrid V+/ progenies. Our results suggest that additional viral gene(s) are required for the formation of wild type V+ ATI.
authors.affiliation: Department of Microbiology and Virology, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway.
authors.forename: Malachy Ifeanyi
authors.initials: MI
authors.lastname: Okeke
authors.forename: Olayiwola A
authors.initials: OA
authors.lastname: Adekoya
authors.forename: Ugo
authors.initials: U
authors.lastname: Moens
authors.forename: Morten
authors.initials: M
authors.lastname: Tryland
authors.forename: Terje
authors.initials: T
authors.lastname: Traavik
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Nilssen
mesh_terms: D015608:Cowpox virus / Q000235:genetics; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D006801:Humans; D007181:Inclusion Bodies, Viral / Q000821:virology*; D018155:Orthopoxvirus / Q000235:genetics* / Q000302:isolation & purification*; D010641:Phenotype; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D014616:Vaccinia virus / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics*
chemical_list: C071902:ATI protein, Vaccinia virus; D004279:DNA, Viral; D014764:Viral Proteins