Persistence drives gene clustering in bacterial genomes

Area of Science:

• Microbiology
• Genomics
• Bioinformatics

Background:

• Gene clustering is crucial for bacterial chromosome organization, but its underlying mechanisms remain debated.
• Previous models overlooked gene function and presence/absence patterns, failing to differentiate between persistent and rare genes.

Purpose of the Study:

• To investigate the distinct clustering patterns of persistent and rare genes in bacterial genomes.
• To propose and validate a model explaining the clustering of persistently present genes.

Main Methods:

• Analysis of gene presence/absence and clustering in bacterial genomes.
• Development of a theoretical model for gene clustering dynamics.
• Testing of selective processes like co-transcription and functional neighborhood for cluster stabilization.

Main Results:

• Both rare and highly persistent genes are significantly clustered in bacterial genomes.
• Rare gene clustering aligns with the selfish operon theory.
• Persistent gene clustering results from indispensability and gene flux, leading to transient clusters.

Conclusions:

• Strong selective pressure on persistent gene function, coupled with constant gene flux, drives persistent gene clustering in bacterial genomes.
• The observed clustering is maintained by ongoing gene deletion and insertion processes.
• Additional selective mechanisms may further stabilize these gene clusters.