Although some disorders of mitochondrial dynamics result from monogenic mutation, most reflect changes in the function or activity of fission and fusion mediators triggered by changes in the cellular milieu. 4 In contrast, disorders of mitochondrial structure are just emerging as mechanisms of disease. Examples of these syndromes include the MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes caused by mutation of mitochondrial transfer RNAs), and Leigh's disease (caused by mutations in genes related to oxidative phosphorylation). 4 Mutations in 228 nuclear and 13 mitochondrial genes cause rare monogenic syndromes in which mitochondrial dysfunction is unequivocally central to the pathogenesis of the disease. Most mitochondrial proteins, including all those involved in fission and fusion, are nuclear-encoded. 1 in the Supplementary Appendix, available with the full text of this article at ). They noted, “Any one type of mitochondria such as a granule, rod or thread may at times change into any other type or may fuse with another mitochondrium, or it may divide into one or several mitochondria.” 3 The once secret, dynamic lives of mitochondria are revealed by confocal, live-cell imaging with the use of potentiometric dyes or mitochondria-targeted fluorescent proteins (see Fig. 2 Lewis and Lewis's 1914 observations established the field of mitochondrial dynamics. 1 First described as “bioblasts” by Altmann in 1890, it was Benda's 1898 observation of their heterogeneous morphologic features, sometimes ball-shaped and other times linear, that inspired the name mitochondrion, from the Greek words mitos (meaning thread) and chondrion (meaning granule). Mitochondria are derived from eubacterial endosymbionts that are capable of aerobic respiration this finding was proposed independently by Merezhkovsky in 1905 and by Margulis in 1967. They continuously join by the process of fusion and divide by the process of fission. Mitochondria are mobile organelles that exist in dynamic networks. The most trusted, influential source of new medical knowledge and clinical best practices in the world. Information and tools for librarians about site license offerings. Valuable tools for building a rewarding career in health care. The authorized source of trusted medical research and education for the Chinese-language medical community. The most advanced way to teach, practice, and assess clinical reasoning skills. Information, resources, and support needed to approach rotations - and life as a resident. The most effective and engaging way for clinicians to learn, improve their practice, and prepare for board exams. NEW! Peer-reviewed journal featuring in-depth articles to accelerate the transformation of health care delivery.Ĭoncise summaries and expert physician commentary that busy clinicians need to enhance patient care. The original concept of this nuclei splitting was discovered by Enrico Femi in 1934-who believed transuranium elements might be produced by bombarding uranium with neutrons, because the loss of Beta particles would increase the atomic number.NEW! A digital journal for innovative original research and fresh, bold ideas in clinical trial design and clinical decision-making. Nuclear fission is the splitting of the nucleus of an atom into nuclei of lighter atoms, accompanied by the release of energy, brought on by a neutron bombardment. The resulting fission products are highly radioactive, commonly undergoing \(\beta^-\) decay. \( \newcommand\) which is even more unstable and splits into daughter nuclei such as Krypton-92 and Barium-141 and free neutrons.
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