Introns

Definition

Introns are non-coding sequences of DNA within a gene that are removed during RNA splicing. They do not encode protein sequences and are transcribed into pre-mRNA but not translated into proteins.

5 Must Know Facts For Your Next Test

1. Introns are found in eukaryotic genes but are generally absent in prokaryotes.
2. During RNA splicing, introns are removed from the pre-mRNA, and exons are joined together to form mature mRNA.
3. The presence of introns allows for alternative splicing, which can produce multiple protein variants from a single gene.
4. Introns often contain regulatory elements that can influence gene expression.
5. Mutations in intron regions can affect splicing and lead to various genetic disorders.

Review Questions

• What is the main role of introns during RNA processing?
• How do introns contribute to protein diversity in eukaryotic cells?
• Why might mutations in intron regions impact gene function?

Related terms

Exon: Coding sequences of DNA within a gene that remain in the mRNA after RNA splicing and code for proteins.

RNA Splicing: The process by which introns are removed from pre-mRNA and exons are joined to form mature mRNA.

Alternative Splicing: A mechanism by which different combinations of exons are joined together to produce multiple mRNA variants from a single gene.