Mitochondrial dynamics and inheritance during cell division, development and disease

Mitochondria contain a genome that is inherited maternally; this complicates their segregation during cell division, oogenesis and development. Mechanisms that ensure mitochondrial integrity include fusion and fission processes, organelle transport, mitophagy and genetic selection. Defects in these processes can lead to cell and tissue pathologies. During cell division, it is critical to properly partition functional sets of organelles to each daughter cell. The partitioning of mitochondria shares some common features with that of other organelles, particularly in the use of interactions with cytoskeletal elements to facilitate delivery to the daughter cells. However, mitochondria have unique features — including their own genome and a maternal mode of germline transmission — that place additional demands on this process. Consequently, mechanisms have evolved to regulate mitochondrial segregation during cell division, oogenesis, fertilization and tissue development, as well as to ensure the integrity of these organelles and their DNA, including fusion–fission dynamics, organelle transport, mitophagy and genetic selection of functional genomes. Defects in these processes can lead to cell and tissue pathologies.