Evolving kinetics of gene expression in stochastic environments

Area of Science:

• Molecular Biology
• Evolutionary Biology
• Systems Biology

Background:

• Bacterial RNA and protein levels are regulated by transcription kinetics.
• Transcription kinetics are influenced by DNA sequence and rate-limiting steps.
• Environmental factors can impact bacterial gene expression dynamics.

Purpose of the Study:

• To investigate the evolutionary advantages of different transcription kinetics.
• To model how mutations affecting transcription kinetics are selected under varying environmental pressures.
• To understand the relationship between environmental constraints and gene expression noise.

Main Methods:

• Computational modeling of gene expression kinetics in individual bacterial cells.
• Simulation of mutations impacting rate-limiting transcription steps.
• Analysis of selective pressures in simulated environments with resource depletion and varying nutrient costs for cell division.

Main Results:

• Small changes in evolutionary constraints can lead to significant differences in RNA and protein number noise levels.
• Increased nutrient costs for cell division favor noisier gene expression.
• Resource depletion impacts bacterial survival and gene expression patterns.

Conclusions:

• Bacterial gene expression noise is adaptable and influenced by evolutionary trade-offs.
• The kinetics of gene expression can evolve to suit specific environmental conditions.
• Understanding transcription kinetics provides insight into the diversity of gene expression patterns in bacteria.