Editing Mitochondrion (section)

===Lack of mitochondrial DNA===
Some organisms have lost mitochondrial DNA altogether. In these cases, genes encoded by the mitochondrial DNA have been lost or transferred to the nucleus.<ref name="Chan-2006"/> ''[[Cryptosporidium]]'' have mitochondria that lack any DNA, presumably because all their genes have been lost or transferred.<ref name="Henriquez-2005">{{cite journal | vauthors = Henriquez FL, Richards TA, Roberts F, McLeod R, Roberts CW | title = The unusual mitochondrial compartment of Cryptosporidium parvum | journal = Trends in Parasitology | volume = 21 | issue = 2 | pages = 68–74 | date = February 2005 | pmid = 15664529 | doi = 10.1016/j.pt.2004.11.010 }}</ref> In ''Cryptosporidium'', the mitochondria have an altered [[Adenosine triphosphate|ATP]] generation system that renders the parasite resistant to many classical mitochondrial [[enzyme inhibitor|inhibitors]] such as [[cyanide]], [[azide]], and [[atovaquone]].<ref name="Henriquez-2005"/> Mitochondria that lack their own DNA have been found in a marine parasitic [[dinoflagellate]] from the genus ''[[Amoebophrya]]''. This microorganism, ''A. cerati'', has functional mitochondria that lack a genome.<ref>{{cite journal | vauthors = John U, Lu Y, Wohlrab S, Groth M, Janouškovec J, Kohli GS, Mark FC, Bickmeyer U, Farhat S, Felder M, Frickenhaus S, Guillou L, Keeling PJ, Moustafa A, Porcel BM, Valentin K, Glöckner G | title = An aerobic eukaryotic parasite with functional mitochondria that likely lacks a mitochondrial genome | journal = Science Advances | volume = 5 | issue = 4 | pages = eaav1110 | date = April 2019 | pmid = 31032404 | pmc = 6482013 | doi = 10.1126/sciadv.aav1110 | bibcode = 2019SciA....5.1110J }}</ref> In related species, the mitochondrial genome still has three genes, but in ''A. cerati'' only a single mitochondrial gene — the [[Cytochrome c oxidase subunit I|cytochrome c oxidase I]] gene (''cox1'') — is found, and it has migrated to the genome of the nucleus.<ref>{{Cite web|url=https://www.sciencedaily.com/releases/2019/04/190424153617.htm|title=Veritable powerhouse{{snd}}even without DNA: Parasitic algae from the dinoflagellate lineage have organized their genetic material in an unprecedented way|website=ScienceDaily|access-date=May 8, 2019|archive-date=June 24, 2019|archive-url=https://web.archive.org/web/20190624001930/https://www.sciencedaily.com/releases/2019/04/190424153617.htm|url-status=live}}</ref>