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Jaan Mannik

@jaanmannik.bsky.social

Professor of biophysics at the University of Tennessee, Knoxville. Studying self-organizing processes in bacterial cells and their cell cycle. volweb.utk.edu/~jmannik/

Posts Replies Media

Jaan Mannik @jaanmannik.bsky.social · 30/11/2025

📢Our MD simulation is out in Biophysical Journal! The nonequilibrium polysome dynamics expands bacterial nucleoids and helps separate daughter chromosomes. Results agree with our previous experiments and extend our earlier model. authors.elsevier.com/a/1mBGt_9FM7... #Microbiology #Biophysics

Snapshot of a model showing two chromosomes (red spheres on the left and yellow ones on the right) before they are fully separated. Kymographs (bottom row) show the density of two daughter chromosomes (left) and ribosomes (right) as a function of time in the presence of nonequilibrium reactions of ribosomes. Blue corresponds to low and red to high density. As time progresses, the two chromosomes separate, but only when the reactions are present. The snapshot above corresponds to time t = 0 in the kymographs.

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Jaan Mannik @jaanmannik.bsky.social · 09/11/2025

Our latest work is out in PNAS!🎉 We show that nonequilibrium polysome dynamics help drive sister chromosomes apart. The closing division septum also contributes via steric interactions.👇 www.pnas.org/doi/10.1073/... #MicroSky #Microbiology #Biophysics #CellBiology

Diagram of an E. coli cell showing polysomes pushing sister chromosomes apart. Bottom heatmaps show cell-cycle-dependent
changes in DNA and ribosome density distributions, and constriction formation. The top right corner shows normalized mid cell amounts from these heatmaps (integrated between the dashed horizontal lines).

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Reposted by Jaan Mannik

Jaana Mannik @jaanamannik.bsky.social · 09/04/2025

Bacteria lack a mitotic spindle—how do they segregate chromosomes? 🤓 Using quantitative microscopy and modeling, we show that polysome (mRNA–ribosome) dynamics contribute to chromosome separation in E. coli, but septum closure and potentially DNA entropic segregation mechanisms are also involved.

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Jaan Mannik @jaanmannik.bsky.social · 17/11/2024

New exciting findings on E. coli cell division: Using high throughput imaging 🔬 & stochastic modeling, we show that FtsZ—not FtsN—drives constriction at fast growth rates. Great collaboration with @arielamir.bsky.social and @KarPrathitha www.nature.com/articles/s41... #Microbiology #CellBiology

nature.com

Determining the rate-limiting processes for cell division in Escherichia coli - Nature Communications

The recruitment of protein FtsN to midcell is thought to be the main rate-liming process for cell division in the bacterial model E. coli. Here, Männik et al. use experiments with live bacteria as wel...

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