Variation in G + C-content and codon choice: differences among synonymous codon groups in vertebrate genes.

Area of Science:

• Genomics
• Molecular Biology
• Bioinformatics

Background:

• Codon usage bias is a significant feature of genome evolution.
• The relationship between genomic G + C-content and codon selection is complex and varies across species.
• Understanding these patterns provides insights into evolutionary pressures and gene expression regulation.

Purpose of the Study:

• To investigate the correlation between G + C-content and codon usage in nuclear genomes of human, mouse, rat, bovine, and chicken.
• To identify specific amino acids and codon groups that exhibit the strongest dependence on G + C-content.
• To explore the relationship between G + C-content, codon usage, and taxonomic distance.

Main Methods:

• Correlation and linear regression analyses were performed on codon frequencies.
• Plots were generated relating codon frequency within synonymous groups to overall G + C-content.
• Comparative genomic analysis across five species was conducted.

Main Results:

• A preferential selection of C-ending codons was observed in most codon groups under GC pressure.
• Exceptions were noted in leucine and valine codon groups, favoring G-ending codons.
• Codons for phenylalanine and glutamate showed the most significant dependence on G + C-content.
• The observed patterns in G + C-content and codon usage correlated with taxonomic distance among the studied species.

Conclusions:

• Genomic G + C-content is a significant driver of codon usage bias in these vertebrate genomes.
• Specific amino acid codons exhibit differential sensitivity to GC pressure.
• The correlation between G + C-content, codon usage, and taxonomic distance suggests evolutionary conservation and divergence patterns.