Hypervariable region
A hypervariable region (HVR) is a location within nuclear DNA or the D-loop of mitochondrial DNA in which base pairs 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. CITATION NEEDED
Nuclear
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Mitochondrial
In some bony fishes, 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 (Plecoglossus altivelis), an East Asian 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.[1]
Antibodies
In antibodies, hypervariable regions form the antigen-binding site and are found on both light and heavy chains.[2] They also contribute to the specificity of each antibody.[2] In a variable region, the 3 HV segments of each heavy or light chain fold together at the N-terminus to form an antigen binding pocket.
See also
- Cambridge Reference Sequence
- Genealogical DNA test
- Human mitochondrial DNA haplogroup
- mtDNA control region
References
- ^ 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)
- ^ a b Michael Stein; Paul Zei; Gloria Hwang; Radhika Breaden (2000). Cracking The Boards: USMLE Step 1. The Princeton Review. Retrieved 5 September 2011.
Antibodies are remarkably specific, thanks to hypervariable regions in both light and heavy chains. The hyperbariable regions for the antigen-binding site.
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External links
- Hypervariable+region at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
- DNA: Forensic and Legal Applications, Explanation of Hypervariable Regions