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mitochondrial DNA (mtDNA),
species of DNA present in mitochondria, where it participates in energy metabolism, rather than in the nucleus.
n. Abbr. mtDNA
DNA that is contained in the mitochondria of eukaryotic cells and is inherited maternally.
mitochondrial DNA A small circular DNA molecule of which all MITOCHONDRIA in cells have several copies. It contains 16,569 base pairs and 37 genes. Being present in the cytoplasm of the cell, is transmitted exclusively by the mother. A mature ovum contains about 100,000 copies of mitochondrial DNA; sperms contain none. The genome has been completely sequenced. Its main function is to code for enzymes needed by the mitochondrion. The sites of common mutations, especially deletions, are known as are a number of diseases caused by these defects in the mitochondrial DNA. See MITOCHONDRIAL DNA DISEASES.
mitochondrial DNA (mtDNA) the DNA GENOME in the MITOCHONDRION that codes for a number of the organelle's functions. The genome is replicated and transcribed by a separate set of ENZYMES from those of the eukaryotic cell NUCLEUS. In METAZOANS the mtDNA is generally circular, and there appear to be no INTRONS. The GENETIC CODE shows differences from the universal code.