GC content evolution in coding regions of angiosperm genomes: a unifying hypothesis

Area of Science:

• Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• GC content variability across and within genomes is a known phenomenon, but its underlying causes remain unclear.
• Grass genomes exhibit distinctive GC content patterns, including bimodal distributions and 5'-3' decreasing gradients along genes.

Purpose of the Study:

• To propose a unifying model explaining GC content variation at gene and genome scales in angiosperms.
• To investigate the roles of gene structure, recombination, and GC-biased gene conversion in shaping GC content patterns.

Main Methods:

• Developing a theoretical model integrating gene structure, recombination patterns, and GC-biased gene conversion.
• Analyzing existing fine-scale recombination maps in angiosperms to support the proposed model.

Main Results:

• The proposed model successfully explains major GC content variation patterns observed in angiosperm genomes.
• Interactions between gene structure, recombination, and GC-biased gene conversion are identified as key determinants of GC content.

Conclusions:

• The unifying model provides a robust framework for understanding GC content variation in angiosperms.
• The model can serve as a null hypothesis for identifying other factors influencing GC content in plant genomes.