The serial endosymbiosis theory holds that mitochondrial predecessors capitalized on a symbiotic relationship by fusing with an early-stage nucleated cell. This successful partnership was then conserved in the ensuing evolutionary explosion. Mitochondrial genetics has become important because mitochondrial DNA mutations have been implicated in an increasing number of diseases. 2 Thirty-seven genes encoded within the 16,569 base pairs of the mitochondrial genome have been identified. To compensate, mtDNA repair occurs at glacial speed compared to the nuclear machinery.
Many researchers use cell-free systems to study mitochondrial pathways.
This usually entails treating populations of cells with different reagents, separating the various cellular components, recombining the components from the different treatments, and studying the effect on mitochondrial processes. The first step in mitochondrial isolation is cell disruption. Although many disruption methods exist, some are better than others for isolating intact mitochondria. Arguably, the simplest is sonication, although this method is better suited to production of whole cell lysates. Many researchers use mortar and pestle style tissue grinders for organelle isolation.