ABOVE: © Lucy reading-ikkanda
For 1.5 billion years, the mitochondrial and nuclear genomes have been coevolving. Over this time, the mitochondrial genome became reduced, retaining only 37 genes in most animal species, and growing reliant on the nuclear genome to fulfill the organelle’s primary function—to produce ATP by oxidative phosphorylation. Mitochondrial gene products interact with those encoded in nuclear genes, and sometimes with the nuclear genome itself. Because the mitochondrial genome mutates faster than the nuclear genome, it takes the lead in the mitonuclear evolutionary dance, while the nuclear genome follows, evolving compensatory mutations to maintain coadapted gene complexes. Researchers are now coming to appreciate that this has consequences for physiology and even macroevolution.
Researchers have long known that many proteins are made of several components, some of which are coded for in the mitochondrial genome, and others being coded for in the nuclear genome. Cytochrome oxidase, the last enzyme ...
