Fig. 1

Most lineages retain relatively stable mitochondrial genomic coding capacities. A cladogram starting with LECA depicts the differential evolution of mitochondrial genomic coding capacities in widely divergent eukaryotic lineages. Though exceptions to these trends are present in various groups, several lineages retain mitochondrial genome coding capacities typical for their clade. CII indicates retention of (some) complex II subunits; ccm indicates retention of subunits of the multicomponent bacteria-derived c-type cytochrome biogenesis system. Purple lineage: largest set of mitochondrial genes; orange lineages: retention of an intermediate number of mitochondrial genes; red lineages: retention of the ‘core set’ of mitochondrial genes only; black lineages: more extensive mitochondrial gene transfer and loss including transfer or loss of all ribosomal genes—usually contains fragmented rRNAs. Asterisks indicate lineages displaying large variations in mitochondrial gene content. For further information, see the main text