Duplication ( lat. Duplicatio - doubling) - a kind of chromosomal rearrangement , in which the portion of the chromosome is doubled. May occur as a result of unequal crossing-over , errors in homologous recombination , retrotransposition [1] .
Duplications can occur within the same chromosome or arise as a result of transferring a copy of a chromosome portion to another chromosome (transposition). Repeats arising on the same chromosome can be arranged in the form of direct or inverted tandem repeats.
Cases of multiple repetitions of a chromosome region known as amplification are known [2] .
In evolution, duplication can result in the formation of repeated nucleotide sequences, gene clusters, and multi-gene families [3] .
When a gene is duplicated, the second copy of the gene is often not subjected to selection pressure - for example, mutation of one of the copies of the gene does not harm the body. Therefore, copies accumulate mutations faster than genes that exist in a single copy.
Duplication is the opposite of gene deletion .
Notes
- ↑ Zhang J. Evolution by gene duplication: an update (English) // Trends in Ecology & Evolution : journal. - Cell Press 2003. - Vol. 18 , no. 6 . - P. 292-298 . - DOI : 10.1016 / S0169-5347 (03) 00033-8 .
- ↑ Inge-Vechtomov S.G. Genetics with the basics of selection. - SPb. : Publishing House NL, 2010. - S. 193—194. - 718 p. - ISBN 978-5-94869-105-3 .
- ↑ Tarantula V.Z. Explanatory biotechnological dictionary. Russian-English. - M .: Languages of Slavic cultures, 2009 .-- 936 p. - ISBN 978-5-9551-0342-6 .