Complex tissue flows in epithelia arise from the coordination of mechanical forces, where cell shape anisotropy and nematic order play a significant role. By introducing internal viscous dissipation in an active nematic vertex model, this study explains the emergence of organised, long-range flows in epithelial sheets, linking cellular dynamics to continuum active nematic and collective cell migration.

Carcinoma subtypes are normally linked to specific genetic alterations, but tissue mechanical changes also play a role. Now, aberrant morphologies resembling bladder carcinoma are shown to emerge from stiffness changes during epithelial overgrowth.

Identifying mutations in pathogen genomes that confer transmission advantages could improve understanding of viral biology and flag variants for further study. Here, the authors develop a model for identifying mutations that affect transmission rates, validate it in simulations, then apply it to SARS-CoV-2 genomic surveillance data.

Sujit Datta discusses how scaling arguments, dimensional analysis and chemical engineering fundamentals can be used to describe microbial swimming.

The cell cortex consists of a chemical and a mechanical subsystem, but how energy is allocated between them is unknown. Now, measurements of the entropy production rate have revealed what determines the cell cortex’s energy budget.

A platform for imaging traction forces exerted by moving cells overcomes current reconstruction limitations. This technique has identified unknown migration dynamics of immune cells and resolved traction forces of single and multicellular systems.

The Fisher information imposes a fundamental limit on the precision with which an unknown parameter can be estimated from noisy data, as Dorian Bouchet explains.

Understanding the mechanism of bacterial cell division is important in both fundamental and applied biology. Now, researchers have investigated the self-organization of cytoskeletal filaments and the role nematic ordering plays in cell division.