Selection on synonymous sites for increased accessibility around miRNA binding sites in plants

Area of Science:

• Molecular Biology
• Genomics
• Evolutionary Biology

Background:

• Synonymous codon usage is influenced by various biological mechanisms in prokaryotes and eukaryotes.
• MicroRNA (miRNA) function may impact synonymous codon selection near miRNA target sites.

Purpose of the Study:

• To investigate synonymous codon usage patterns around miRNA target sites in plant genomes.
• To understand the relationship between site accessibility, GC content, and miRNA target site selection.

Main Methods:

• Genome-wide analysis of synonymous codon usage in four plant genomes.
• Analysis of site accessibility and GC content around miRNA target sites.
• Examination of factors like gene GC content, codon usage bias, and conservation.

Main Results:

• Increased site accessibility observed around plant miRNA target sites.
• Preference for Guanine-Cytosine (GC)-poor codons in the flanking regions of miRNA target sites.
• GC content of target genes explains variations in site accessibility; GC-rich genes show stronger selection.

Conclusions:

• Synonymous codons near miRNA targets are selected to facilitate efficient miRNA binding and function.
• This selection represents a novel aspect of natural selection on synonymous codons in plants.
• Findings have significant implications for understanding coding sequence evolution.