A hypervariable region (HVR) is a location within nuclear DNA or the D-loop of

mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...

in which

base pair A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

s of nucleotides 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.

Mitochondrial

There are two MITOCHONDRIAL hypervariable regions used in human mitochondrial genealogical DNA testing. 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. In the revised Cambridge Reference Sequence of the human mitogenome, the most variable sites of HVR1 are numbered 16024-16383 (this subsequence is called HVR-I), and the most variable sites of HVR2 are numbered 57-372 (''i.e.,'' HVR-II) and 438-574 (''i.e.,'' HVR-III).''PhyloTree mt''
"Annotated mtDNA reference sequences: revised Cambridge Reference Sequence (rCRS)"
Retrieved on 4 February 2016. In some

bony fish Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...

es, for example certain Protacanthopterygii and Gadidae, the mitochondrial control region evolves remarkably slowly. Even functional mitochondrial genes accumulate mutations faster and more freely. It is not known whether such hypovariable control regions are more widespread. In the

Ayu Ayu or AYU may refer to: * Ayu (given name) * Ayu sweetfish (''Plecoglossus altivelis''), a species of smelt * ''Ayu'', a local name for the African manatee * Ayu (singer) or Ayumi Hamasaki, Japanese singer * Ayu Islands, a small archipelago in I ...

(''Plecoglossus altivelis''), an East Asian protacanthopterygian, control region mutation rate is not markedly lowered, but sequence differences between

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

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. (HTML abstract)

Antibodies

antibodies An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...

, hypervariable regions form the antigen-binding site and are found on both light and heavy chains. They also contribute to the specificity of each antibody. In a variable domain, the 3 H_V segments of each heavy or light chain fold together at the

N-terminus The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...

to form an antigen binding pocket.

References

External links

* {{MeshName, Hypervariable+region
DNA: Forensic and Legal Applications, Explanation of Hypervariable Regions
Genetic genealogy Genetic engineering Antibodies

Mitochondrial

Antibodies

See also

References

External links