This study investigates the physical mechanics of cytokinesis, specifically focusing on how a contractile band forms and functions during cell division in zebrafish embryos. Researchers utilized advanced microscopy techniques and specialized tools like magnetic and optical tweezers to measure the viscoelastic properties of the cell’s internal structure. Their findings suggest that the actin cortex is not the primary anchor for the contractile band, challenging existing models of how cells partition. Through laser ablation experiments and numerical simulations, the authors demonstrate how mechanical tension and flow contribute to the ingression of the cell membrane. Ultimately, the paper provides a detailed biophysical profile of the forces that drive successful cytoplasmic partitioning in a living vertebrate model.

References:

• Kickuth A, Uršič U, Staddon M F, et al. A mechanical ratchet drives unilateral cytokinesis[J]. Nature, 2026: 1-9.