Mitochondrial Heterosis

It has been demonstrated with corn, barley and wheat that in single-cross hybrids oxidative phosphorylation activity of mitochondria is similar to that of mixtures of parental mitochondria. In most examples studied where these hybrids exhibited heterosis for a productive trait there was also heterosis for oxidative phosphorylation of mitochondria. Investigations of mitochondrial heterosis in animals are few. It has been shown that heterosis in a hybrid of two Drosophila lines is correlated with heterosis of mitochondria. Mechanisms for explaining mitochondrial heterosis include formation of “hybrid” mitochondria, production of heterotic mitochondrial enzymes and introduction of missing cytochromes. Oxidative phosphorylation information on mixtures of mitochondria may be useful in assessing lines for cross performance.