title: Genome sequencing identifies genetic and antigenic divergence of porcine picobirnaviruses.
abstract: The full-length genome sequence of a porcine picobirnavirus (PBV) detected in Italy in 2004 was determined. The smaller (S) genome segment was 1730 nt, coding for a putative RNA-dependent RNA polymerase. Two distinct subpopulations of larger (L) genome segment (LA and LB) were identified in the sample, with the sizes ranging from 2351 to 2666 nt. The ORF1, coding for a protein of unknown function, contained a variable number of repetitions of the ExxRxNxxxE motif. The capsid protein-coding ORF2 spanned nt 810-2447 in the LB variants and started at nt 734 in the LA variants. However, a termination codon was present only in one of all the LA segment variants. Three-dimensional modelling of the porcine PBV capsids suggested structural differences in the protruding domain, tentatively involved as antigens in the humoral immune response. Altogether, these findings suggest the simultaneous presence of two different PBV strains sharing the same S segment but displaying genetically diverse L segments. In addition, the sample probably contained a mixture of PBVs with aberrant RNA replication products. Altered structure in the L segments could be tolerated and retained in the presence of functionally integer-cognate genes and represents a mechanism of virus diversification.
authors.affiliation: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary.
authors.forename: Krisztián
authors.initials: K
authors.lastname: Bányai
authors.affiliation: Department of Biochemistry, Centre for Human Metabonomics, North-West University, Potchefstroom, South Africa.|Virology Division, Onderstepoort Veterinary Institute, Onderstepoort, South Africa.
authors.forename: Christiaan
authors.initials: C
authors.lastname: Potgieter
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary.
authors.forename: Ákos
authors.initials: Á
authors.lastname: Gellért
authors.affiliation: Division of Virology, National Institute of Cholera and Enteric Diseases (NICED), Kolkata, West Bengal, India.
authors.forename: Balasubramanian
authors.initials: B
authors.lastname: Ganesh
authors.affiliation: Dipartimento di Medicina Veterinaria, Università di Bari Aldo Moro, Bari, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Tempesta
authors.affiliation: Dipartimento di Medicina Veterinaria, Università di Bari Aldo Moro, Bari, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Lorusso
authors.affiliation: Dipartimento di Medicina Veterinaria, Università di Bari Aldo Moro, Bari, Italy.
authors.forename: Canio
authors.initials: C
authors.lastname: Buonavoglia
authors.affiliation: Dipartimento di Medicina Veterinaria, Università di Bari Aldo Moro, Bari, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Martella
mesh_terms: D000818:Animals; D000940:Antigenic Variation; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology; D016000:Cluster Analysis; D014644:Genetic Variation; D016679:Genome, Viral; D007558:Italy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D018708:Picobirnavirus / Q000145:classification / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D011487:Protein Conformation; D012327:RNA Virus Infections / Q000662:veterinary* / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D013552:Swine; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D000956:Antigens, Viral; D012367:RNA, Viral; D014764:Viral Proteins