Genetic Differentiation of the Mitochondrial Cytochrome Oxidase <i>c</i> Subunit I Gene in Genus <i>Paramecium</i> (Protista, Ciliophora)

Abstract

<div><p>Background</p><p>The mitochondrial cytochrome <i>c</i> oxidase subunit I (<i>COI</i>) gene is being used increasingly for evaluating inter- and intra-specific genetic diversity of ciliated protists. However, very few studies focus on assessing genetic divergence of the <i>COI</i> gene within individuals and how its presence might affect species identification and population structure analyses.</p><p>Methodology/Principal findings</p><p>We evaluated the genetic variation of the <i>COI</i> gene in five <i>Paramecium</i> species for a total of 147 clones derived from 21 individuals and 7 populations. We identified a total of 90 haplotypes with several individuals carrying more than one haplotype. Parsimony network and phylogenetic tree analyses revealed that intra-individual diversity had no effect in species identification and only a minor effect on population structure.</p><p>Conclusions</p><p>Our results suggest that the <i>COI</i> gene is a suitable marker for resolving inter- and intra-specific relationships of <i>Paramecium</i> spp.</p></div