Intraspecific and within-isolate sequence variation in the ITS rRNA gene region of Pythium mercuriale sp. nov. (Pythiaceae)

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dc.contributor.authorBelbahri L.
dc.contributor.authorMcLeod A.
dc.contributor.authorPaul B.
dc.contributor.authorCalmin G.
dc.contributor.authorMoralejo E.
dc.contributor.authorSpies C.F.J.
dc.contributor.authorBotha W.J.
dc.contributor.authorClemente A.
dc.contributor.authorDescals E.
dc.contributor.authorSanchez-Hernandez E.
dc.contributor.authorLefort F.
dc.date.accessioned2011-05-15T16:04:56Z
dc.date.available2011-05-15T16:04:56Z
dc.date.issued2008
dc.description.abstractSixteen Pythium isolates from diverse hosts and locations, which showed similarities in their morphology and sequences of the internal transcribed spacer (ITS) region of their rRNA gene, were investigated. As opposed to the generally accepted view, within single isolates ITS sequence variations were consistently found mostly as part of a tract of identical bases (A-T) within ITS1, and of GT or GTTT repeats within the ITS2 sequence. Thirty-one different ITS sequences obtained from 39 cloned ITS products from the 16 isolates showed high sequence and length polymorphisms within and between isolates. However, in a phylogenetic analysis, they formed a cluster distinct from those of other Pythium species. Additional sequencing of two nuclear genes (elongation factor 1α and β-tubulin) and one mitochondrial gene (nadh1) revealed high levels of heterozygosity as well as polymorphism within and between isolates, with some isolates possessing two or more alleles for each of the nuclear genes. In contrast to the observed variation in the ITS and other gene areas, all isolates were phenotypically similar. Pythium mercuriale sp. nov. (Pythiaceae) is characterized by forming thin-walled chlamydospores, subglobose to obovoid, papillate sporangia proliferating internally and smooth-walled oogonia surrounded by multiple antheridia. Maximum likelihood phylogenetic analyses based on both ITS and β-tubulin sequence data place P. mercuriale in a clade between Pythium and Phytophthora. © 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.
dc.description.versionArticle
dc.identifier.citationFEMS Microbiology Letters
dc.identifier.citation284
dc.identifier.citation1
dc.identifier.issn3781097
dc.identifier.other10.1111/j.1574-6968.2008.01168.x
dc.identifier.urihttp://hdl.handle.net/10019.1/12896
dc.subjectbeta tubulin
dc.subjectelongation factor 1alpha
dc.subjectinternal transcribed spacer
dc.subjectribosome RNA
dc.subjectallele
dc.subjectarticle
dc.subjectcontrolled study
dc.subjectgene sequence
dc.subjectheterozygosity
dc.subjectmitochondrial gene
dc.subjectmolecular cloning
dc.subjectnonhuman
dc.subjectnucleotide sequence
dc.subjectphylogeny
dc.subjectpriority journal
dc.subjectPythium
dc.subjectPythium mercuriale
dc.subjectAlgal Proteins
dc.subjectAlleles
dc.subjectCluster Analysis
dc.subjectDNA, Algal
dc.subjectDNA, Ribosomal
dc.subjectDNA, Ribosomal Spacer
dc.subjectGenes, rRNA
dc.subjectGenotype
dc.subjectHeterozygote
dc.subjectMolecular Sequence Data
dc.subjectPeptide Elongation Factor 1
dc.subjectPhenotype
dc.subjectPhylogeny
dc.subjectPolymorphism, Genetic
dc.subjectPythium
dc.subjectSequence Analysis, DNA
dc.subjectTubulin
dc.subjectOomycetes
dc.subjectPhytophthora
dc.subjectPythiaceae
dc.subjectPythium
dc.titleIntraspecific and within-isolate sequence variation in the ITS rRNA gene region of Pythium mercuriale sp. nov. (Pythiaceae)
dc.typeArticle
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