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Hearing silence: non-neutral evolution at synonymous sites in mammals
J V Chamary1, Joanna L Parmley, Laurence D Hurst
1Center for Integrative Genomics, University of Lausanne, Switzerland. j.v.chamary@unil.ch
Nature Reviews. Genetics
|January 19, 2006
Summary
The neutral theory of molecular evolution is being challenged. New evidence shows that even synonymous mutations, often assumed neutral, can be constrained by natural selection, impacting disease and genetic research.
Area of Science:
- Molecular Evolution
- Genetics
- Bioinformatics
Background:
- The neutral theory of molecular evolution posits that most mutations have negligible fitness effects and are not subject to natural selection.
- This assumption has been widely accepted but is increasingly being challenged by new evidence.
- In many species, even synonymous mutations within exons are not neutral.
Purpose of the Study:
- To re-evaluate the assumption of neutrality for synonymous mutations in mammals.
- To present new evidence demonstrating constraint on synonymous mutations in mammals.
- To explore the functional impact of these non-neutral synonymous mutations.
Main Methods:
- Analysis of synonymous mutations in mammalian genomes.
- Investigation of potential functional impacts on splicing and mRNA stability.
- Comparative genomics and evolutionary analyses.
Main Results:
- Contrary to common assumptions in mammalian studies, evidence indicates that some synonymous mutations are under constraint.
- These constrained synonymous mutations frequently impact critical RNA processing events, such as splicing and mRNA stability.
- This constraint suggests these mutations are not neutral and are influenced by natural selection.
Conclusions:
- The assumption of widespread neutrality for synonymous mutations in mammals is likely incorrect.
- Synonymous mutations can play significant roles in cellular processes and disease.
- Understanding these constraints is crucial for accurate disease gene identification, transgene design, and evolutionary rate estimation.
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