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Inference of expression-dependent negative selection based on polymorphism and divergence in the human genome
1Department of Biomedical Resources, National Institute of Biomedical Innovation, Osaka, Japan. nosada@nibio.go.jp
Molecular Biology and Evolution
|May 5, 2007
Summary
Gene expression patterns significantly influence human genome evolution. Genes expressed in the brain show fewer amino acid changes, while liver-expressed genes exhibit more, indicating strong selective pressures on gene evolution.
Area of Science:
- Genomics
- Evolutionary Biology
- Molecular Biology
Background:
- Evidence links gene expression patterns to sequence divergence.
- The relationship between gene expression and genetic polymorphism remains less understood.
Purpose of the Study:
- To investigate the influence of gene expression patterns on genetic polymorphism and divergence in the human genome.
- To explore the correlation between gene expression breadth and the rates of nonsynonymous to synonymous substitutions.
Main Methods:
- Compiled human genome data on gene expression, polymorphism, and divergence from public databases.
- Analyzed ratios of nonsynonymous (A) to synonymous (S) substitutions in relation to gene expression patterns across various tissues.
- Correlated gene expression breadth with amino acid changes during polymorphism and divergence.
Main Results:
- Gene expression patterns and breadth strongly correlate with the ratios of nonsynonymous to synonymous substitutions in human polymorphism and divergence.
- Brain-expressed genes show the lowest proportion of amino acid changes, while liver-expressed genes show the highest.
- Genes under relaxed negative selection evolve faster but are more susceptible to slightly deleterious mutations.
Conclusions:
- Negative selection is a key factor shaping expression-dependent gene evolution and the distribution of slightly deleterious mutations.
- Highly conserved genes, like brain-expressed and housekeeping genes, effectively eliminate deleterious mutations before they enter the population.
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