Numt

Numt (pronounced “new might”) is an abbreviated term for “nuclear mitochondrial DNA”, which describes any transfer or “transposition” of cytoplasmic mitochondrial DNA sequences into the separate nuclear genome of a eukaryotic organism. As whole genome sequencing projects accumulate, more and more Numts have been detected in many diverse eukaryotic organisms (see http://www.pseudogene.net for one list of examples).

The first use of the term was made to describe a transposition of approximately 7.9 kilobase pairs of the cytoplasmic mtDNA genome into the nucleus of the domestic cat (Felis silvestris catus), where Numt is tandemly repeated, 38-76 times at a single genomic locus on cat chromosome D2. Many Numts are transcriptionally inactive similar to some satellite (or junk) DNA, though they may be considered as part of the Serial Endosymbios Theory or endosymbiotic theory for the origin of eukaryotic cells and organelles.