Intron

An intron is a non-coding sequence in a gene.

It is any nucleotide sequence within a gene that is removed by RNA splicing to get the final RNA product of a gene.^[1][2] The term intron refers to both the DNA sequence within a gene, and the corresponding sequence in RNA transcripts.^[3]

Sequences of coding DNA which are joined together in the final RNA after RNA splicing are exons. They code for amino acids in the final polypeptide.

Introns are in the genes of most organisms and many viruses. They can be in a wide range of genes, including those that generate proteins, ribosomal RNA (rRNA), and transfer RNA (tRNA). RNA splicing takes place after transcription and before translation.

• Introns: parts of a gene which are discarded: non-working bits.
• Exons: parts of a gene which are expressed: bits of a gene which code for amino-acid sequences in a protein.

The discovery of introns led to the Nobel Prize in Physiology or Medicine in 1993 for Phillip Sharp and Richard Roberts. The term intron was introduced by American biochemist Walter Gilbert.^[4]

1. ↑ Alberts, Bruce (2008). Molecular biology of the cell. New York: Garland Science. ISBN 978-0-8153-4105-5.
2. ↑ Stryer, Lubert; Berg, Jeremy Mark; Tymoczko, John L. (2007). Biochemistry. San Francisco: W.H. Freeman. ISBN 978-0-7167-6766-4.{{cite book}}: CS1 maint: multiple names: authors list (link)
3. ↑ Kinniburgh, Alan; Mertz J. and Ross J. (1978). "the precursor of mouse β-globin messenger RNA contains two intervening RNA sequences". Cell. 14 (3): 681–693. doi:10.1016/0092-8674(78)90251-9. PMID 688388. S2CID 21897383.{{cite journal}}: CS1 maint: multiple names: authors list (link)
4. ↑ Gilbert, Walter (1978). "Why genes in pieces". Nature. 271 (5645): 501. Bibcode:1978Natur.271..501G. doi:10.1038/271501a0. PMID 622185. S2CID 4216649.