Sequencing and Analysis of the Complete Organellar Genomes of .

Of the genus, has the highest clinical significance in humans. However, neither nuclear nor organellar genomes of this species were sequenced until now. The hitherto determined and analyzed mitochondrial and plastid genomes of the alleged species belong in fact to another species, recently named e. This study provides a first insight into the organellar genomes of a true (type strain ATCC 16529). The mitochondrion had a 53.8-kb genome, which was considerably larger than that of (formerly gen. 1) and (formerly gen. 2), yet similarly functional, with the differences in size attributable to a higher number of introns and the presence of extra unique putative genes. The 48-kb plastid genome of , compared to autotrophic Trebouxiophyceae, was highly reduced due to the elimination of the photosynthesis-related genes. The gene content of the plastid genome of was, however, very similar to other colorless species. Plastid genome-based phylogeny reinforced the polyphyly of the genus , with and branching within clades of species. Phylogenetic reconstruction also confirmed the close relationship of and , which is reflected in the synteny of their organellar genomes. Interestingly, the entire set of genes was lost in plastid genome while being preserved in .