Fig. 1: Time evolution of mitotic waves.
From: Spatial heterogeneity accelerates phase-to-trigger wave transitions in frog egg extracts
a Schematic view of the experimental preparation of cycling egg extracts in Teflon tubes. Bottom-Left: The regulatory network driving mitotic oscillations. b Top: Representative FRET ratio kymograph for extracts without sperm DNA. Color bar indicates FRET ratio. Two wavefronts are labeled in white (dashed, early time; solid, later time). The local wave speed is the inverse of the wavefront slope (dt/dx). Bottom: FRET ratio time course recorded at x = 10 mm. The period is defined as the interval between consecutive FRET ratio peaks. One early time region, T1, and one later time region, T2, are selected for (c). c Shifted mean-corrected FRET ratio for T1 and T2. Top: T1 showing in-phase activation with no clear wavefront. Bottom: T2 showing a traveling pulse, indicated by an arrow. Bidirectional arrows beside the colorbar indicate T1 and T2. d Time evolution of the period (top), slope (middle), and wave speed (bottom). Period and slope distributions (grayscale colormap) represent the time-normalized kernel density estimation. The solid curves show the locally weighted scatterplot smoothing (LOWESS) estimations. The speed here is the inverse of the slope’s LOWESS estimation. The onset of exponential decay (τ0, dashed blue line) is calculated via a moving horizon fitting (see Supplementary Fig. 1). The speed after τ0 is fitted by an exponential function (solid red line) to calculate the entrainment time (Δτ). The horizontal black line indicates the fitted terminal speed (vt) and the vertical dashed black line indicates τ0 + Δτ. e Speed-period relationship. Local measurements of the period and speed are represented by gray dots (2 % of all data points were shown). Combined speed-period relation (solid black line) is computed from the LOWESS estimations in (d). Markers (open circles with grayscale fillings) indicate multiples of 100 min (except for the first, shown for clarity). Color bar indicates time. The transition time points τ0 and τ0 + Δτ are indicated on a dashed guideline with the transition window highlighted in red. Data in (d, e) are pooled from two independent egg batches with three replicates each (n = 6).
