Hypervariable region 5565217 192040959 2008-02-17T11:09:40Z Wizzy 39004 not always a repeat A '''hypervariable region''' (HVR) is a location within [[nuclear DNA]] or the [[D-loop]] of [[mitochondrial DNA]] in which [[base pair]]s of [[nucleotide]]s repeat (in the case of nuclear DNA) or have substitutions (in the case of mitochondrial DNA). Changes or repeats in the hypervariable region are highly [[Polymorphism (biology)|polymorphic]]. There are two mitochondrial hypervariable regions used in human mitochondrial [[genealogical DNA test]]ing. HVR1 is considered a "low resolution" region and HVR2 is considered a "high resolution" region. Getting HVR1 and HVR2 DNA tests can help determine one's [[Human mitochondrial DNA haplogroup|haplogroup]]. HVR1 locations are numbered 16001-16568. HVR2 locations are numbered 001-574. In some [[bony fish]]es, for example certain [[Protacanthopterygii]] and [[Gadidae]], the mitochondrial control region evolves remarkably slowly. Even functional mitochondrial [[gene]]s accumulate mutations faster and more freely. It is not known whether such hypovariable control regions are more widespread. In the [[Ayu]] (''Plecoglossus altivelis''), an [[East Asia]]n protacanthopterygian, control region [[mutation]] rate is not markedly lowered, but sequence differences between [[subspecies]] are far lower in the control region than elsewhere. This phenomenon completely defies explanation at present.<ref>Takeshima, Hirohiko; Iguchi, Kei-ichiro & Nishida, Mutsumi (2005): Unexpected Ceiling of Genetic Differentiation in the Control Region of the Mitochondrial DNA between Different Subspecies of the Ayu ''Plecoglossus altivelis''. ''[[Zoological Science|Zool. Sci.]]'' '''22'''(4): 401–410. <small>{{doi|10.2108/zsj.22.401}}</small> (HTML abstract)</ref> ==References== {{Reflist}} ==See also== *[[Human mitochondrial DNA haplogroup]] *[[Genealogical DNA test]] *[[Cambridge Reference Sequence]] ==External links== * {{MeshName|Hypervariable+region}} [[Category:Genetic genealogy]] [[Category:Genetics]] [[Category:Genetic engineering]] [[cs:Hypervariabilní oblast]]