intron

American  

[in-tron] / ˈɪn trɒn /

noun

Genetics.

1. a noncoding segment in a length of DNA that interrupts a gene-coding sequence or nontranslated sequence, the corresponding segment being removed from the RNA copy before transcription.

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intron British  

/ ˈɪntrɒn /

noun

1. biochem a stretch of DNA that interrupts a gene and does not contribute to the specification of a protein Compare exon 2

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intron Scientific  

/ ĭn′trŏn /

1. A segment of a gene situated between exons that does not function in coding for protein synthesis. After transcription of a gene to messenger RNA, the transcriptions of introns are removed, and the exons are spliced together by enzymes before translation and assembly of amino acids into proteins.

2. Compare exon

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intron Cultural  

1. A stretch of DNA in a gene that does not code for proteins. In eukaryotes, introns in a given gene separate stretches of DNA that contain instructions for constructing proteins. (Compare exon.)

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Etymology

Origin of intron

1975–80; perhaps intr(o)- + -on ¹

Example Sentences

If the spliceosome is able to reinsert the intron into DNA, this would also add significant weight to the theory that spliceosomes and Group II introns shared a common ancestor long ago.

From Science Daily • May 10, 2024

Only finished mRNAs that have undergone 5' capping, 3' polyadenylation, and intron splicing are exported from the nucleus to the cytoplasm.

From Textbooks • Jun. 9, 2022

For example, a single exon gene on the opposite strand and in the last intron of the early developmental growth factor spätzle encodes a 42-amino-acid protein that is highly conserved across all sequenced Drosophila species.

From Nature • Mar. 15, 2014

An even more sprawling gene—dystrophin, the Jacksonville of human DNA—contains 14,000 bases of coding DNA spread among 2.2 million bases of intron cruft.

From Slate • Jul. 12, 2012

For example, a mutation in the apoE4 gene, associated with Alzheimer’s disease risk, puts part of an intron into the protein.

From Scientific American • May 16, 2012