Intramitochondrial recombination – is it why some mitochondrial genes sleep around?

A new paper by Kajander et al. undermines the general view that mitochondria do not recombine. The authors discovered the existence of ‘sublimons’, rearranged mitochondrial genomes present at very low levels in healthy human patients. Crucially, the different rearranged mitochondrial genomes can theoretically be interconverted through intramitochondrial recombination. The putative operation of intramitochondrial recombination should impact on our ideas of how mitochondrial genes evolve, particularly with respect to how mitochondrial genomes rearrange.