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]]