Skip to main content
Fig. 5 | BMC Biology

Fig. 5

From: Single-cell genomics unveils a canonical origin of the diverse mitochondrial genomes of euglenozoans

Fig. 5

The evolutionary history of mtDNA in euglenozoans. Mitochondrial traits were mapped onto a schematic phylogenetic tree based on this and previous studies [2, 28, 30, 32, 43]. The ancestral discobid-like mtDNA. For the last common ancestor of euglenozoans, mtDNA was represented by a circular-mapping chromosome, meaning of TGA codon was changed to code for W, and genes for atp1, 3, 8, and 9, sdh3, and 4, and majority of mitoribosomal proteins were transferred to the nucleus. After separation of EU17/18, rps2, rpl2, and nad11 underwent endosymbiotic gene transfer (EGT). For the common euglenid ancestor, mtDNA was fragmented to chromosomes with single genes and mito-rRNAs were split to halves. Majority of genes encoding NADH dehydrogenase, rps12, and 13, and rpl14 were transferred to the nucleus, and rps14 was lost. For the glycomonads, genes were split to modules and rRNAs were significantly shortened. While rps14 underwent EGT, rps13 and rpl14 were lost completely. Mitochondrial genome structure of early-branching euglenids is currently unknown. For the SAG EU2, chromosomes encoding single genes were joined to a possibly circular molecule, resembling the ancestral state. Diplonemids acquired diverse RNA editing mechanism to produce mature transcripts. After separation of SAG D1, mtDNA of the rest of kinetoplastids was catenated into interlocked mini- and maxicircles. Primary transcripts are processed by U-insertion/deletion RNA editing to restore the coding sequence

Back to article page