Mitochondrial genome
235337
220370997
2008-06-19T15:12:26Z
DOI bot
6652755
Citation maintenance. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]].
The '''mitochondrial genome''' is the genetic material of the [[mitochondria]]. The [[mitochondria]] are [[organelle]]s that reproduce themselves semi-autonomously within [[eukaryote|eukaryotic]] cells.
The genetic material forming the mitochondrial [[genome]] is similar in structure to that of the [[prokaryote|prokaryotic]] genetic material. The mitochondrial chromosome is a circular [[DNA]] molecule, but unlike prokaryotes it is much smaller and several copies are present. This similarity supports the hypothesis that mitochondria arose from intracellular bacterial symbiotes, ''i.e.'' the [[endosymbiotic theory]].
The [[mitochondria]] of a sexually-reproducing species are generally inherited maternally. (There are exceptions, such as among the [[gymnosperms]], in which some families inherit mitochondria or [[chloroplasts]] paternally). In animals, mitochondrial genetic diseases can affect both males and females, but can only be transmitted by females to their offspring (see, however, http://en.wikipedia.org/wiki/Mitochondrion#_note-32 for evidence of low-level Paternal transmission of mitochondrial DNA). The human mitochondrial genome consists of 16,569 base pairs, which encodes only 13 proteins, 22 tRNAs, and 2 rRNAs.
Compared to the [[genome|nuclear genome]], the mitochondrial genome possesses some very interesting features:
* All the genes are carried on a single circular DNA molecule.
* The genetic material is not bounded by a nuclear envelope.
* The DNA is not packed into [[chromatin]].
* The genome contains little non-coding DNA ([[Junk DNA|"junk" DNA]], or [[introns]]).
* Some codons do not follow the universal rules in translation. Instead they resemble those of [[Purple bacteria|purple non-sulfur bacteria]].
* Some bases are considered part of two different genes: both as the last base of one gene and as the first base of the next gene.
==See also==
* [[mitochondrial DNA]]
* [[Human mitochondrial genetics]]
==References==
*{{cite journal
| last = San Mauro
| first = Diego
| title = A hotspot of gene order rearrangement by tandem duplication and random loss in the vertebrate mitochondrial genome
| url = http://mbe.oxfordjournals.org/cgi/reprint/23/1/227
| journal = Molecular Biology and Evolution
| volume = 23
| pages = 227–234
| year = 2006
| month = January
| coauthors = David J. Gower, Rafael Zardoya and Mark Wilkinson
| doi = 10.1093/molbev/msj025
| pmid = 16177229
}}
* Wolstenholme, D.R. 1992. Animal mitochondrial DNA: structure and evolution. Int. Rev. Cytol. 141: 173-216
==External links==
*[http://www.ncbi.nlm.nih.gov/genomes/framik.cgi?gi=12188&db=Genome Map of the human mitochondrial genome (Human Genome Project)]
*[http://www.ncbi.nlm.nih.gov:80/genomes/ORGANELLES/organelles.html Sequence data and related info (NCBI Organelle Genome Resources)]
*[http://www.mitomap.org Other mitochondrial info (Mitomap database)]
[[Category:Molecular genetics]]
[[Category:Genomics]]
[[Category:Mitochondria]]
[[ca:Genoma mitocondrial]]
[[es:Genoma mitocondrial]]
[[he:גנום מיטוכונדריאלי]]
[[sr:Митохондријски геном]]
[[zh:线粒体基因组]]