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Phylogenetic relationships among diploid Aegilops species inferred from 5S rDNA units.
Mol Phylogenet Evol. 2009 Oct; 53(1):34-44.MP

Abstract

Relationships among the currently recognized 11 diploid species within the genus Aegilops have been investigated. Sequence similarity analysis, based upon 363 sequenced 5S rDNA clones from 44 accessions plus 15 sequences retrieved from GenBank, depicted two unit classes labeled the long AE1 and short AE1. Several different analytical methods were applied to infer relationships within haplomes, between haplomes and among the species, including maximum parsimony and maximum likelihood analyses of consensus sequences, "total evidence" phylogeny analysis and "matrix representation with parsimony" analysis. None were able to depict suites of markers or unit classes that could discern among the seven haplomes as is observed among established haplomes in other genera within the tribe Triticeae; however, most species could be separated when displayed on gene trees. These results suggest that the haplomes currently recognized are so refined that they may be relegated as sub-haplomes or haplome variants. Amblyopyrum shares the same 5S rDNA unit classes with the diploid Aegilops species suggesting that it belongs within the latter. Comparisons of the Aegilops sequences with those of Triticum showed that the long AE1 unit class of Ae. tauschii shared the clade with the equivalent long D1 unit class, i.e., the putative D haplome donor, but the short AE1 unit class did not. The long AE1 unit class but not the short, of Ae. speltoides and Ae. searsii both share the clade with the previously identified long {S1 and long G1 unit classes meaning that both Aegilops species can be equally considered putative B haplome donors to tetraploid Triticum species. The semiconserved nature of the nontranscribed spacer in Aegilops and in Triticeae in general is discussed in view that it may have originated by processes of incomplete gene conversion or biased gene conversion or birth-and-death evolution.

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Authors+Show Affiliations

Baum BR
Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre, Neatby Building, 960 Carling Avenue, Ottawa, Ont., Canada K1A 0C6. baumbr@agr.gc.ca
Edwards T
No affiliation info available
Johnson DA
No affiliation info available

MeSH

Base SequenceConsensus SequenceDNA, PlantDNA, RibosomalDiploidyEvolution, MolecularGenome, PlantLikelihood FunctionsModels, GeneticMolecular Sequence DataPhylogenyPoaceaeSequence Analysis, DNATriticum

Pub Type(s)

Journal Article

Language

eng

PubMed ID

19527789

Citation

Baum, B R., et al. "Phylogenetic Relationships Among Diploid Aegilops Species Inferred From 5S rDNA Units." Molecular Phylogenetics and Evolution, vol. 53, no. 1, 2009, pp. 34-44.
Baum BR, Edwards T, Johnson DA. Phylogenetic relationships among diploid Aegilops species inferred from 5S rDNA units. Mol Phylogenet Evol. 2009;53(1):34-44.
Baum, B. R., Edwards, T., & Johnson, D. A. (2009). Phylogenetic relationships among diploid Aegilops species inferred from 5S rDNA units. Molecular Phylogenetics and Evolution, 53(1), 34-44. https://doi.org/10.1016/j.ympev.2009.06.005
Baum BR, Edwards T, Johnson DA. Phylogenetic Relationships Among Diploid Aegilops Species Inferred From 5S rDNA Units. Mol Phylogenet Evol. 2009;53(1):34-44. PubMed PMID: 19527789.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Phylogenetic relationships among diploid Aegilops species inferred from 5S rDNA units. AU - Baum,B R, AU - Edwards,T, AU - Johnson,D A, Y1 - 2009/06/13/ PY - 2008/10/17/received PY - 2009/06/02/revised PY - 2009/06/09/accepted PY - 2009/6/17/entrez PY - 2009/6/17/pubmed PY - 2009/9/15/medline SP - 34 EP - 44 JF - Molecular phylogenetics and evolution JO - Mol Phylogenet Evol VL - 53 IS - 1 N2 - Relationships among the currently recognized 11 diploid species within the genus Aegilops have been investigated. Sequence similarity analysis, based upon 363 sequenced 5S rDNA clones from 44 accessions plus 15 sequences retrieved from GenBank, depicted two unit classes labeled the long AE1 and short AE1. Several different analytical methods were applied to infer relationships within haplomes, between haplomes and among the species, including maximum parsimony and maximum likelihood analyses of consensus sequences, "total evidence" phylogeny analysis and "matrix representation with parsimony" analysis. None were able to depict suites of markers or unit classes that could discern among the seven haplomes as is observed among established haplomes in other genera within the tribe Triticeae; however, most species could be separated when displayed on gene trees. These results suggest that the haplomes currently recognized are so refined that they may be relegated as sub-haplomes or haplome variants. Amblyopyrum shares the same 5S rDNA unit classes with the diploid Aegilops species suggesting that it belongs within the latter. Comparisons of the Aegilops sequences with those of Triticum showed that the long AE1 unit class of Ae. tauschii shared the clade with the equivalent long D1 unit class, i.e., the putative D haplome donor, but the short AE1 unit class did not. The long AE1 unit class but not the short, of Ae. speltoides and Ae. searsii both share the clade with the previously identified long {S1 and long G1 unit classes meaning that both Aegilops species can be equally considered putative B haplome donors to tetraploid Triticum species. The semiconserved nature of the nontranscribed spacer in Aegilops and in Triticeae in general is discussed in view that it may have originated by processes of incomplete gene conversion or biased gene conversion or birth-and-death evolution. SN - 1095-9513 UR - https://www.unboundmedicine.com/medline/citation/19527789/Phylogenetic_relationships_among_diploid_Aegilops_species_inferred_from_5S_rDNA_units_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1055-7903(09)00227-9 DB - PRIME DP - Unbound Medicine ER -