title: Twenty-fold difference in evolutionary rates between the mitochondrial and plastid genomes of species with secondary red plastids.
abstract: Within plastid-bearing species, the relative rates of evolution between mitochondrial and plastid genomes are poorly studied, but for the few lineages in which they have been explored, including land plants and green algae, the mitochondrial DNA mutation rate is nearly always estimated to be lower than or equal to that of the plastid DNA. Here, we show that in protists from three distinct lineages with secondary, red algal-derived plastids, the opposite is true: their mitochondrial genomes are evolving 5-30 times faster than their plastid genomes, even when the plastid is nonphotosynthetic. These findings have implications for understanding the origins and evolution of organelle genome architecture and the genes they encode.
authors.affiliation: Department of Botany, Canadian Institute for Advanced Research, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada. smithdr@dal.ca
authors.forename: David Roy
authors.initials: DR
authors.lastname: Smith
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Keeling
mesh_terms: D001403:Babesia / Q000235:genetics; D005075:Biological Evolution; D056890:Eukaryota / Q000166:cytology / Q000235:genetics*; D019143:Evolution, Molecular; D054629:Genome, Mitochondrial; D054627:Genome, Plastid; D058087:Haptophyta / Q000235:genetics; D008928:Mitochondria / Q000235:genetics*; D008969:Molecular Sequence Data; D059645:Mutation Rate; D018087:Plastids / Q000235:genetics*; D000461:Rhodophyta / Q000235:genetics*