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Chromosome segregation in B. subtilis is highly heterogeneous
Nina El Najjar1,2, Peter L Graumann3,4
1LOEWE Center for Synthetic Microbiology, SYNMIKRO, Philipps Universität Marburg, Marburg, Germany.
BMC Research Notes
|October 10, 2020
Summary
Bacillus subtilis cells show heterogeneous chromosome numbers during cell division, even under DNA damage. Most cells attempt to maintain multiple chromosomes, indicating robust replication and segregation processes.
Area of Science:
- Microbiology
- Molecular Biology
- Cell Biology
Background:
- The bacterial cell cycle involves DNA replication, segregation, and cell division.
- Understanding cell cycle parameters is crucial for bacterial growth dynamics.
Purpose of the Study:
- To quantify replication origins and termini in Bacillus subtilis.
- To determine cell cycle parameters at single-cell resolution.
- To investigate these parameters under varying growth rates and DNA damage.
Main Methods:
- Quantification of origin and terminus regions in Bacillus subtilis.
- Analysis of cell populations during exponential growth.
- Assessment after induction of DNA damage.
Main Results:
- Bacillus subtilis cells exhibit mero-oligoploid to diploid chromosome numbers depending on growth rate.
- High heterogeneity in chromosome copy numbers was observed within cell populations.
- Cells maintained multiple chromosomes and continued replication/segregation post-DNA damage.
Conclusions:
- Bacterial chromosome replication and segregation are robust processes.
- Heterogeneity in chromosome numbers may indicate subpopulations with different growth rates.
- Cells actively manage chromosome copy numbers throughout the cell cycle.
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