Physiological roles of mitochondrial fission in cultured cells and mouse development.

Mitochondria, which are double-membrane organelles thought to have originated through endosymbiosis of bacteria, play important roles in not only energy production, but also cellular signaling, differentiation, and development. The morphology of mitochondria is highly diverse among different tissues, and dynamic changes in mitochondrial morphology have been observed in response to various intracellular signals and stresses. These changes in mitochondrial morphology occur by repeated membrane fusion and fission events, which are regulated by three types of GTPase proteins: OPA1, Mfn1/2, Drp1 in mammalian cells. In recent years, the function and molecular mechanisms of mitochondrial dynamics have been demonstrated in cultured cells; however, the role of mitochondrial fission in maintaining tissue homeostasis remains poorly understood. Here, we review recent advances in research on the physiological role of mitochondrial fission in various differentiated tissue types in mammals.