intron

noun

in·​tron ˈin-ˌträn 

: a polynucleotide sequence in a nucleic acid that does not code information for protein synthesis and is removed before translation of messenger RNA compare exon

Examples of intron in a Sentence

Recent Examples on the Web

The coding sections of genes are interrupted by introns, which don’t encode for anything. — ArsTechnica, 4 Mar. 2026

The results from this study indicate that the murine C3a receptor structural gene is a single copy gene of approximately 8 kb comprised of 2 exons which are separated by a large intervening intron of 4724 bp. — Kirstin R.w. Matthews, STAT, 3 Feb. 2026

Several mechanisms that could create introns have been identified, and all of them may have contributed some introns to eukaryotes. — Jake Buehler, Quanta Magazine, 30 Mar. 2023

There are now about a dozen individual changes in the amino acids used to make the protein, and the nearby DNA has picked up both an insertion (an intron) and several deletions. — John Timmer, Ars Technica, 23 Feb. 2018

Word History

Etymology

intervening sequence + -on entry 2

First Known Use

1978, in the meaning defined above

Medical Definition

intron

noun

in·​tron ˈin-ˌträn 

: a polynucleotide sequence in a nucleic acid that does not code information for protein synthesis and is removed before translation of messenger RNA compare exon

intronic

in-ˈträn-ik 

adjective