Gene amplification

Definition

A process that increases the copy number of a specific gene or chromosomal region without a proportional increase in other genes; occurs through natural mechanisms such as unequal crossing-over, rolling-circle replication, or chromosomal rearrangement, or through laboratory techniques including polymerase chain reaction (PCR) and whole-genome amplification. In arthropods, natural gene amplification is a major adaptive mechanism, notably in the evolution of metabolic resistance to insecticides.

Etymology

Example

In the mosquito *Culex pipiens*, amplification of the *CYP6Z1* cytochrome P450 gene family enhances detoxification of pyrethroid insecticides, while in the cattle tick *Rhipicephalus microplus*, esterase gene amplification underlies organophosphate resistance.

Synonyms

• Gene duplication
• DNA amplification

Related Terms

• Gene duplication
• polymerase chain reaction
• copy number variation
• metabolic resistance
• unequal crossing-over
• rolling-circle replication
• whole-genome amplification
• insecticide resistance

Usage Notes

Distinguish from 'gene duplication,' which often implies heritable, stable copy-number increase integrated into the genome, whereas 'gene amplification' may include transient, unstable, or experimentally induced copy-number gains. In medical/veterinary entomology, PCR-based gene amplification is essential for detecting pathogen DNA in vectors; in evolutionary biology, natural gene amplification drives rapid adaptation to environmental toxins.