Transcription-replication interactions reveal bacterial genome regulation

Area of Science:

• Genomics and Molecular Biology
• Bacterial Gene Regulation
• Systems Biology

Background:

• Gene expression is regulated by a few recurring modes across genomes.
• Bacterial gene regulation is understood for individual circuits but lacks genome-wide dynamics.
• Current transcriptomics provide static, averaged snapshots, obscuring expression diversity.

Purpose of the Study:

• To develop a genome-wide classification of regulatory modes.
• To analyze the relationship between gene regulatory architecture and expression dynamics.
• To understand gene expression heterogeneity using a novel framework.

Main Methods:

• Introduced the transcription-replication interaction profile (TRIP) for genome-wide classification.
• Utilized single-bacterium RNA-sequencing data.
• Analyzed transcriptional response to chromosomal replication as a perturbation.

Main Results:

• Identified TRIPs as a method integrating regulatory factors and biophysical events.
• Found that TRIPs reveal the local regulatory context of genes.
• Observed gene dosage-dependent patterns and distinct deviations shaped by operon position and repression.

Conclusions:

• The transcription-replication interaction profile (TRIP) provides a novel framework for understanding gene expression.
• Replication-dependent expression dynamics are influenced by a combination of regulatory and biophysical factors.
• This work offers a quantitative, biophysical model for replication-dependent gene expression heterogeneity.