There is growing appreciation among evolutionary biologists for the central role of mitochondria and oxidative phosphorylation (OXPHOS) in the rise of metazoans (Lane and Martin, 2010). The result is an expanding focus on the integration of mitochondrial and nuclear genomes and the implications of such integration for topics as disparate as sex, aging, cancer and flight (Lane, 2005). In the transition from free-living organism to organelle, mitochondria transferred the great majority of their genes to the nucleus, retaining in vertebrates only 13 genes that code for proteins along with two genes that code for rRNA and 22 genes that code for tRNA (Bar-Yaacov et al., 2012). Mitochondria depend on about 1500 nuclear genes whose products function in the mitochondria (N-mt genes). A subset of these N-mt genes forms complexes with mitochondrial genes (mt genes), and these mitonuclear constructs function as key translational and OXPHOS machinery within mitochondria (Bar-Yaacov et al., 2012).