title: Population differentiation and selective constraints in Pelargonium line pattern virus.
abstract: The genomic structure of Pelargonium line pattern virus (PLPV), a tentative member of a proposed new genus within the family Tombusviridae, has been recently determined. However, little is known about the genetic variability and population structure of this pathogen. Here, we have investigated the heterogeneity of PLPV isolates from different origins by sequence analysis of a 1817nt fragment encompassing the movement (p7 and p9.7) and coat protein genes as well as flanking segments including the complete 3' untranslated region. We have evaluated the selective pressures operating on both viral proteins and RNA genome in order to assess the relative functional and/or structural relevance of different amino acid or nucleotide sites. The results of the study have revealed that distinct protein domains are under different selective constraints and that maintenance of certain primary and/or secondary structures in RNA regulatory sequences might be an important factor limiting viral heterogeneity. We have also performed covariation analyses to uncover potential dependencies among amino acid sites of the same protein or of different proteins. The detection of linked amino acid substitutions has permitted to draw a putative network of intra- and interprotein interactions that are likely required to accomplish the different steps of the infection cycle. Finally, we have obtained phylogenetic trees that support geographical segregation of PLPV sequences.
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, CPI, Ed 8E, Camino de Vera s/n, 46022 Valencia, Spain.
authors.forename: Aurora
authors.initials: A
authors.lastname: Castaño
authors.forename: Leticia
authors.initials: L
authors.lastname: Ruiz
authors.forename: Santiago F
authors.initials: SF
authors.lastname: Elena
authors.forename: Carmen
authors.initials: C
authors.lastname: Hernández
mesh_terms: D016000:Cluster Analysis; D014644:Genetic Variation; D008969:Molecular Sequence Data; D031316:Pelargonium / Q000821:virology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D019183:Tombusviridae / Q000235:genetics* / Q000254:growth & development*; D014764:Viral Proteins / Q000235:genetics
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins