Molecular evolution of angiosperm mitochondrial introns and exons
| Autor: | Jérôme Laroche, Laurent Maggia, Jean Bousquet, Peng Li |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Nonsynonymous substitution
Mutation rate Mitochondrial DNA Nuclear gene F40 - Écologie végétale Génétique mitochondriale Molecular Sequence Data Biology Genes Plant DNA Mitochondrial Ka/Ks ratio F30 - Génétique et amélioration des plantes Electron Transport Complex IV Evolution Molecular Open Reading Frames Exon Molecular evolution Phylogeny Genetics Multidisciplinary Intron Biologie moléculaire Exons Mitochondrie Plants Biological Sciences Structure cellulaire Introns Angiosperme |
| Zdroj: | American Journal of Botany Proceedings of the National Academy of Sciences of the United States of America |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.94.11.5722 |
| Popis: | Numbers of substitutions per site for 15 protein-coding genes and six introns of the plant mitochondria were estimated to compare modes and tempos of evolution between exons and introns, and numbers of insertions–deletions per site also were investigated in introns. Intra-gene homogeneity of numbers of substitutions per site was assessed further among different taxa and between mitochondrial and nuclear paralogs translocated from the mitochondrial genome. Gene-to-gene differences in numbers of substitutions per site were found to be higher for nonsynonymous than synonymous sites, and this could be due to differential selection if mutation rate is assumed constant for the genome. Some mitochondrial genes have evolved as fast as chloroplast genes, thus faster than previously thought. For cox I, relative rate tests showed that woody taxa evolved slower than annuals at synonymous sites. Generation time, population size, and speciation rate are likely factors involved in this rate heterogeneity. Introns were less constrained than their adjacent exons for both overall numbers of substitutions per site and indels, but, on average, overall numbers of substitutions per site for introns were similar to numbers of synonymous substitutions per site for exons. Correlations were generally high between numbers of substitutions and numbers of indels per site for the same intron. Mitochondrial genes transferred to the nucleus had an accelerated rate of substitution per site, which was most significant at synonymous sites. These differences between paralogs in two different genomes are likely the result of different mutation rates. |
| Databáze: | OpenAIRE |
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