Molecular evolution of angiosperm mitochondrial introns and exons

Laroche J., Li P., Maggia Laurent, Bousquet Jean. 1997. Molecular evolution of angiosperm mitochondrial introns and exons. Proceedings of the National Academy of Sciences of the United States of America, 94 (11) : 5722-5727. Joint Annual Meeting of the American Institute of Biological Sciences and Botanical Society of America, États-Unis, 1997.

Autre titre : Evolution moléculaire des introns et exons mitochondriaux des angiospermes

Liste HCERES des revues (en SHS) : oui

Thème(s) HCERES des revues (en SHS) : Economie-gestion; Psychologie-éthologie-ergonomie

Résumé : Numbers of substitutions per site for 15 protein-coding genes and sixintrons 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 non synonymous 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 coxI, relativerate 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.

Mots-clés Agrovoc : Angiosperme, biologie moléculaire, structure cellulaire, génétique mitochondriale, mitochondrie

Classification Agris : F40 - Écologie végétale
F30 - Génétique et amélioration des plantes

Auteurs et affiliations

• Laroche J.
• Li P.
• Maggia Laurent, CIRAD-FORET-FORETS NATURELLES (GUF) ORCID: 0000-0001-9975-9081
• Bousquet Jean, Université Laval (CAN)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/389492/)

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