intron
Definition
An intron is a non-coding DNA sequence within a gene that is transcribed into precursor mRNA but removed during RNA splicing before translation. Found predominantly in eukaryotic genes, introns interrupt the coding sequences (exons) and are excised by the spliceosome complex through a precise cut-and-paste mechanism. While initially considered 'junk DNA,' introns play crucial regulatory roles including alternative splicing to generate protein diversity, gene expression regulation, and evolutionary flexibility. Intron retention or aberrant splicing can lead to disease states. The number and size of introns vary dramatically across species and genes, with some human genes containing over 100 introns. Understanding intron biology is essential for interpreting genomic data, predicting protein isoforms, and identifying splice-site mutations in genetic disorders.
Visualize intron in Nodes Bio
Researchers can visualize splicing networks showing relationships between introns, exons, and splice variants across different tissues or conditions. Network graphs can map splicing factor interactions, display alternative splicing patterns in disease versus normal states, or connect intron retention events to downstream pathway effects. This enables identification of splicing regulatory networks and visualization of how mutations in splice sites propagate through molecular cascades.
Visualization Ideas:
- Splice variant networks showing exon-intron architecture across tissue types
- Splicing factor regulatory networks connecting RNA-binding proteins to intron retention patterns
- Disease-associated splice site mutation networks linking genomic variants to aberrant transcripts
Example Use Case
A cancer genomics team investigating tumor heterogeneity discovers recurrent mutations in splice acceptor sites of the TP53 gene across patient samples. By analyzing RNA-seq data, they identify multiple intron retention events leading to truncated protein isoforms. Using network visualization, they map how these aberrant splice variants correlate with specific cancer subtypes, patient outcomes, and sensitivity to different chemotherapies. The analysis reveals that intron 6 retention creates a dominant-negative p53 variant associated with treatment resistance, suggesting a novel biomarker for therapy selection.