A heteroduplex is a double-stranded (
duplex
Duplex (Latin, 'double') may refer to:
Arts and entertainment
* ''Duplex'' (film), or ''Our House'', a 2003 American black comedy film
* Duplex (band), a Dutch electronic music duo
* Duplex (Norwegian duo)
* Duplex!, a Canadian children's music ...
) molecule of
nucleic acid
Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main cl ...
originated through the
genetic recombination
Genetic recombination (also known as genetic reshuffling) is the exchange of genetic material between different organisms which leads to production of offspring with combinations of traits that differ from those found in either parent. In eukaryo ...
of single complementary strands derived from ''different'' sources, such as from different homologous
chromosomes or even from different
organisms.
One such example is the heteroduplex DNA strand formed in
hybridization
Hybridization (or hybridisation) may refer to:
*Hybridization (biology), the process of combining different varieties of organisms to create a hybrid
*Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals
*Nu ...
processes, usually for
biochemistry-based
phylogenetic analyses. Another is the heteroduplexes formed when non-natural analogs of nucleic acids are used to bind with nucleic acids; these heteroduplexes result from performing
antisense techniques using single-stranded
peptide nucleic acid,
2'-O-methyl phosphorothioate or
Morpholino oligos
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids c ...
to bind with RNA.
In
meiosis, the process of crossing-over occurs between non-sister chromatids, which results in new allelic combinations in the gametes. In crossing-over, a
Spo11
Spo11 is a protein that in humans is encoded by the ''SPO11'' gene. Spo11, in a complex with mTopVIB, creates double strand breaks to initiate meiotic recombination. Its active site contains a tyrosine which ligates and dissociates with DNA to pr ...
enzyme makes staggered nicks in a pair of sister chromatid strands (in a tetrad organization of prophase). Subsequent enzymes trim back the 5' ends of the strand and a protein complex binds to the 3' single-stranded ends. Rad51 protein is recruited and binds in a protein complex to search for a complementary sequence analogous to double-strand-break repair. The filament searches for the homologous chromosome, strand invasion occurs where the new chromosome forms a
D-loop over the bottom sister chromatid, then the ends are annealed. This process can yield double
Holliday junctions that when cut in a transversal pattern by endonucleases form 2 heteroduplex strand products.
Heteroduplex DNA is also a source of
small RNAs (smRNAs), causing post-transcriptional gene silencing.
DNA
{{Biochem-stub