Mitochondrial dynamics and inheritance during cell division, development and disease

Mitochondria are organelles with key roles in cellular metabolism. They have unique cellular dynamics to ensure their proper distribution to dividing cells and high fidelity of inheritance of their genome in a maternal mode of transmission.In mammals, mitochondrial segregation during cell division seems to be primarily a passive process. Mitochondrial fusion, fission, transport, contacts with the endoplasmic reticulum and mitophagy all play a part in maintaining a homogeneous population that is spatially well distributed in the cell soma and that can thus be partitioned equally to daughter cells.Mitochondrial DNA (mtDNA) inheritance from one generation to another is strongly influenced by mtDNA bottlenecks and genetic selection that occur during oogenesis and early embryonic development. Quality-control mechanisms are probably present to minimize the accumulation of pathogenic mutations, which lead to a class of diseases termed mitochondrial encephalomyopathies.The depletion of paternal mitochondria during fertilization is nearly universal in metozoans, although its timing and mechanisms vary substantially between species. Proteasome-dependent degradation, mtDNA degradation and mitophagy have been implicated in this process in different organisms.