Intergenic region
- Pronunciation
- /in-ter-JEE-nik REE-jun/
- Category
- Genetics
- Singular
- intergenic region
- Plural
- intergenic regions
Definition
A segment of that lies between two protein-coding or -coding genes, encompassing the non-transcribed sequences that separate units along a . These regions vary enormously in length—from a few to megabases in —and may harbor functional elements such as (enhancers, silencers, insulators), non-coding RNA genes, origins of replication, or structural chromatin domains, alongside sequences with no currently known function. In , intergenic regions are critical for understanding , compaction in some insects, and the evolution of regulatory networks.
Etymology
From Latin inter- (between) + Greek genēs (born, producing), referring to location between gene loci.
Example
In Drosophila melanogaster, the intergenic region between the Antennapedia and Ultrabithorax contains multiple cis-regulatory elements that control spatial expression patterns during embryonic development; comparative analysis of these regions across Drosophila has revealed how regulatory evolution drives morphological diversification.
Synonyms
- intergenic sequence
- intergenic spacer
- gene desert (when very large)
Related Terms
- Intron
- exon
- promoter
- enhancer
- cis-regulatory element
- non-coding RNA
- Gene regulation
- genome architecture
- Transposable element
Usage Notes
Distinguish from , which are non-coding sequences within a gene that are removed during processing; intergenic regions are outside gene boundaries entirely. The term 'intergenic' is sometimes loosely used to mean 'non-coding,' but reserve it for specifically locations. In compact (e.g., some bacteria, yeast, or gene-dense insect regions), intergenic regions may be minimal, whereas in mammals and some plants they can constitute most of the genome. The presence of functional elements in intergenic regions means 'intergenic' does not equate to 'functionless'—a common misconception.