Intron

Definition

An intron is a non-coding sequence within a gene that is removed during RNA splicing. Introns are transcribed into RNA but are not translated into proteins.

5 Must Know Facts For Your Next Test

1. Introns are found in the genes of eukaryotes but are generally absent in prokaryotic genes.
2. During RNA splicing, introns are removed and exons are joined together to form mature mRNA.
3. The process of removing introns from pre-mRNA involves small nuclear ribonucleoproteins (snRNPs) and the spliceosome complex.
4. Introns can play roles in gene regulation and alternative splicing, leading to different protein products from a single gene.
5. Mutations within intronic regions can affect splicing efficiency and lead to diseases.

Review Questions

• What happens to introns during RNA splicing?
• Are introns found in prokaryotic or eukaryotic genes?
• How can mutations within intronic regions affect an organism?

Related terms

Exon:

A coding sequence within a gene that remains in the final mature mRNA after splicing.

Spliceosome: A complex of snRNPs and other proteins responsible for removing introns from pre-mRNA.

Alternative Splicing: A mechanism by which different forms of mature mRNAs (and thus different proteins) are generated from the same gene.