RT Journal Article SR Electronic T1 Contractile ring composition dictates kinetics of in silico contractility JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.07.06.499011 DO 10.1101/2022.07.06.499011 A1 Daniel B. Cortes A1 Francois Nedelec A1 Amy Shaub Maddox YR 2022 UL http://biorxiv.org/content/early/2022/07/06/2022.07.06.499011.abstract AB Constriction kinetics of the cytokinetic ring are expected to depend on dynamic adjustment of ring composition, but the impact of component abundance dynamics on ring constriction is understudied. Computational models generally assume that contractile networks maintain constant composition. To test how compositional dynamics affect constriction kinetics, we first measured F-actin, non-muscle myosin II, septin, and anillin during C. elegans zygotic mitosis. A custom microfluidic device that positioned the cell with the division plane parallel to a light sheet allowed even illumination of the cytokinetic ring. Measured component abundances were implemented in an agent-based 3D model of a membrane-associated contractile ring. With constant network composition, constriction occurred with biologically unrealistic kinetics. Measured changes in component quantities elicited realistic constriction kinetics. Simulated networks were more sensitive to changes in motor and filament amounts, than that of crosslinkers and tethers. Our findings highlight the importance of network composition for actomyosin contraction kinetics.Summary We created a microfluidic device compatible with high numerical aperture light sheet microscopy to measure cytokinetic ring component abundance in the C. elegans zygote. Implementing measured dynamics into our three-dimensional agent-based model of a contractile ring elicited biologically realistic kinetics.Competing Interest StatementDr. Amy Maddox declares her relationship with Dr. Paul Maddox, who is Chairman of the Board of Directors of Mizar Imaging, LLC. No other authors declare any conflict of interest.