Variation in the ribosomal internal transcribed spacers (ITS1 and ITS2) among eight taxa of the Mimulus guttatus species complex
| Autor: | Carol Ritland, K Ritland, N A Straus |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Species complex
Mimulus guttatus Transcription Genetic Molecular Sequence Data Biology DNA Ribosomal Polymerase Chain Reaction Phylogenetics Sequence Homology Nucleic Acid Genetics Internal transcribed spacer Molecular Biology Ribosomal DNA Mimulus Crosses Genetic Phylogeny Ecology Evolution Behavior and Systematics Base Sequence Genetic Variation Spacer DNA Plants Ribosomal RNA biology.organism_classification Biological Evolution Introns Evolutionary biology Chromosome Inversion Nucleic Acid Conformation Polymorphism Restriction Fragment Length |
| Zdroj: | Molecular Biology and Evolution. |
| ISSN: | 1537-1719 |
| DOI: | 10.1093/oxfordjournals.molbev.a040067 |
| Popis: | The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA sequence and the intervening 5.8S region were sequenced from three individuals in each of eight taxa of the Mimulus guttatus species complex. Three discrete variants, or "types," of ITS sequences were found, among which 30%-40% of sites differed, compared with 1%-2% within types. Dot plots indicate that these types were not related by conspicuous rearrangements or inversions. More than one ITS type was often found in the same taxon, and two of three ITS types span species boundaries, indicating their presence prior to speciation. These ITS sequences showed essentially no positional homology with the nearest sequenced relative, tomato. In contrast, the 5.8S region was relatively unvaried, with 8 of 162 sites varied in the sample among all eight taxa. The phylogeny inferred by the most common ITS sequence type, rooted by the two other ITS types, agreed with isozymes in showing the distinctness of M. nudatus, M. laciniatus, and M. tilingii from the other five taxa. |
| Databáze: | OpenAIRE |
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