| Land plant mitochondrial genomes are larger and have more genes as well as a lower rate of mutation relative to the animal counterparts. It has been suggested that the small mitochondrial genomes present in animals may be a result of a mutational rate bias between the mitochondria and the nucleus, such that a high mutation rate in the mitochondria drove the transfer of genes to the nucleus, which is subject to a lower mutation rate. Green algae present an excellent opportunity to further explore this hypothesis, as they show five fold fewer mitochondrial protein-coding genes in some taxa, such as the genus Chlamydomonas, when compared to earlier branching green algae, for example Nephroselmis olivacea; in terms of the number of genes they encode these two types of green algal mtDNA are similar to those of animals and land plants, respectively. Identification of green algal taxa that are an appropriate evolutionary distance such that Ks can be reliably estimated in the mitochondria and nucleus is crucial to further explore the proposed hypothesis. Thus, the goal of this study is to identify such algae, beginning with the Chlamydomonas taxa. (Abstract shortened by UMI.)... |
