Fig. 2: Cytoplasmic partitioning is intrinsically unstable, but the cell-cycle duration can avoid the instability leading to robust compartmentalization.
From: Robust cytoplasmic partitioning by solving a cytoskeletal instability
a, Live imaging of interphase-arrested cytoplasmic extract showing microtubule aster invasion. Microtubules are shown in green. Aster invasion results in the fusion of cytoplasmic compartments and dynein-induced relocation of sperm nuclei. Cytoplasmic compartments are shown in magenta and nuclei in cyan with GFP-nuclear localization signal (NLS). b, High-resolution timelapse of an invasion event. c, Top view of 3D agent-based simulations of two asters showing the invasion process over time. d, Invasion time plotted against initial mass difference between the asters, showing that asters with small mass differences take longer to invade than asters with large mass differences (40 invasion events from n = 20 independent samples). Error bars are s.e.m. Cell-cycle time of the frog embryo25 is plotted for comparison. Simulations are shown in grey (n = 78 independent simulations), experimental data in blue and theory in orange. The error bars are s.d. e, Phase portrait of the average area of the compartments for arrested (magma; n = 6 independent samples) and cycling extract (viridis; n = 6 independent samples) normalized (norm) for the initial area equal to 1 (dashed line). \(\tau \) = 8 min. Although the area of compartments in arrested extract grows freely, the area of compartments in cycling extract oscillates and maintains a small size, even though some invasion events are present. A is the compartment area. f, Zoomed graph of the phase portrait of the cycling extract. The average cell-cycle time varies from 39 to 65 min (n = 6 independent samples). g, Normalized average compartment area over time. Shades of blue refer to the different cell-cycle times reported in the caption of panel h. Experimental data are shown as dots and binned data with error bars (s.d.). n = 6 independent samples. h, Probability density function (PDF) of normalized average compartment area (n = 6 independent samples).
