Visualization of tandem repeat mutagenesis in Bacillus subtilis

Area of Science:

• Genetics and Microbiology
• Molecular Biology
• Evolutionary Biology

Background:

• Mutations drive protein evolution and life's diversity.
• Tandem repeats (TRs) are genomic hotspots for mutations across all organisms.
• Visualizing TR mutagenesis at the single-cell level requires advanced reporter systems.

Purpose of the Study:

• To develop a mutation reporter system for visualizing TR mutagenesis in single Bacillus subtilis cells.
• To enable measurement of TR unit elimination linked to growth rate recovery.
• To investigate the molecular mechanisms of TR instability and mutation emergence.

Main Methods:

• Development of a specific mutation reporter system for Bacillus subtilis.
• Utilizing microfluidic single-cell cultivation techniques.
• Observing TR unit elimination and mutation emergence in real-time at the single-cell level.

Main Results:

• Successfully visualized the emergence of specific TR mutations in single bacterial cells for the first time.
• Demonstrated the system's capability to measure TR unit loss correlating with growth recovery.
• Provided a platform for observing mutation dynamics under specific conditions.

Conclusions:

• The developed mutation reporter system, coupled with microfluidics, offers unprecedented visualization of TR mutagenesis in single cells.
• This approach can elucidate molecular mechanisms of TR instability in bacteria.
• The system may be valuable for assessing mutation responses to environmental factors like nutrient starvation.