- Hypervariable region
A hypervariable region (HVR) is a location within
nuclear DNA or theD-loop ofmitochondrial DNA in whichbase pair s ofnucleotide 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 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 haplogroup. HVR1 locations are numbered 16001-16568. HVR2 locations are numbered 001-574.In some
bony fish es, for example certainProtacanthopterygii andGadidae , the mitochondrial control region evolves remarkably slowly. Even functional mitochondrialgene s accumulate mutations faster and more freely. It is not known whether such hypovariable control regions are more widespread. In theAyu ("Plecoglossus altivelis"), anEast Asia n protacanthopterygian, control regionmutation rate is not markedly lowered, but sequence differences betweensubspecies are far lower in the control region than elsewhere. This phenomenon completely defies explanation at present. [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". "Zool. Sci." 22(4): 401–410. doi|10.2108/zsj.22.401 (HTML abstract)]References
ee also
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Human mitochondrial DNA haplogroup
*Genealogical DNA test
*Cambridge Reference Sequence External links
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