Exon definition as a potential negative force against intron losses in evolution
2008
Exon Definition and Intron Loss in Evolution
publication
Evidence: moderate
Author Information
Author(s): Niu Deng-Ke
Primary Institution: Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, PR China
Hypothesis
Exon definition may thus be a selective force against intron loss.
Conclusion
The majority of spliceosomal introns in vertebrates may be maintained during evolution not because of potential functions, but because of their splicing mechanism.
Supporting Evidence
- Exon definition constrains the length of exons, which may lead to splicing errors if introns are lost.
- Vertebrates that mainly use exon definition have lower rates of intron loss compared to those that use intron definition.
- Most intron-loss events occur within housekeeping genes, which still have more introns than tissue-specific genes.
Takeaway
This study suggests that how genes are spliced can affect whether introns are lost over time, with exon definition possibly helping to keep more introns.
Limitations
The hypothesis may not apply universally across all eukaryotic lineages.
Digital Object Identifier (DOI)
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