Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA in mitochondria.[1] It is inherited only from mothers, though there are a few rare exceptions.
Mitochondria are cellular organelles in eukaryotic cells. They convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP). Mitochondrial DNA is only a small part of the DNA in a eukaryotic cell. Most of the DNA is in the cell nucleus on chromosomes. In plants, the chloroplasts have DNA as well.
In humans, mitochondrial DNA codes for 37 genes and with about 16,600 base pairs in a circle. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. The mtDNA in plants is much larger: Arabidopsis has 367 kilobytes.
Mitochondrial DNA Media
Mitochondrial DNA is the small circular chromosome found inside mitochondria. These organelles, found in all eukaryotic cells, are the powerhouse of the cell. The mitochondria, and thus mitochondrial DNA, are passed exclusively from mother to offspring through the egg cell.
Illustration of the location of mitochondrial DNA in human cells
Human mitochondrial DNA with the 37 genes on their respective H- and L-strands
Schematic karyogram showing the human genome, with 23 chromosome pairs as well as the mitochondrial genome (to scale at bottom left, annotated "MT"). Its genome is relatively tiny compared to the rest, and its copy number per human cell varies from 0 (erythrocytes) up to 1,500,000 (oocytes).
Human mitochondrial DNA with groups of protein-, rRNA- and tRNA-encoding genes
The involvement of mitochondrial DNA in several human diseases
Animal species mtDNA base composition was retrieved from the MitoAge database and compared to their maximum life span from AnAge database.
References
- ↑ Reference books tend to prefer mtDNA as the abbreviation: Klug W.S. et al 2012. Concepts of genetics. 10th ed, Pearson, p228. ISBN 978-0-321-79578-6; King R.C. et al 2006. A dictionary of genetics. 7th ed, Oxford University Press, p280. ISBN 0-19-530761-5