Mitochondrial DNA

Article By:

Al-Jiab, Rami Department of Anatomy, University of Otago, Dunedin, Otago, New Zealand.

Last reviewed:August 2019

DOI:https://doi.org/10.1036/1097-8542.428230

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• Mitochondrial DNA (mtDNA) and mitochondrial replacement therapy, published April 2015:Download PDF Get Adobe Acrobat Reader

Extrachromosomal DNA contained in the mitochondrion. The mitochondrion (the plural form is mitochondria) is a eukaryotic cellular organelle with the key function of energy production through oxidative phosphorylation. Accordingly, mitochondrial DNA (mtDNA; Fig. 1) mainly contains genes related to oxidative phosphorylation, specifically the electron-transport-chain protein subunits. An organism's entire mtDNA sequence is called its mitogenome. The most dominant theory about the origins of mitochondria is the endosymbiosis hypothesis, under which the mitochondrion (including its mtDNA) is presumed to have originated from a prokaryotic cell that was engulfed by an early eukaryotic ancestor. In particular, this idea is supported by the fact that mtDNA takes on circular forms in many species and largely lacks introns (intervening sequences), which are both features of prokaryotic DNA. See also: Biological oxidation; Cell (biology); Deoxyribonucleic acid (DNA); Eukaryota; Gene; Genetics; Intron; Mitochondria; Prokaryote

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