Extended Data Fig. 10: The primordium is a continuously migrating tissue.
From: Rear traction forces drive adherent tissue migration in vivo
a, Itgb1b-tdTomato-to-Itgb1b-sfGFP (left) and Itgb1b-tdTomato-to-Itgb1bΔNPxY-sfGFP (right) ratio images in trunk muscle cells. Images are single optical slices from z-stacks. Ratios are color-coded as indicated. Scale bar = 25 μm. b, Quantification of ratios Itgb1b-tdTomato to Itgb1b-sfGFP and Itgb1b-tdTomato to Itgb1bΔNPxY-sfGFP at the myotendinous junction and lateral sides of muscle cells. Data points, means, and SD are indicated. ****: p<0.0001 (two-tailed Mann-Whitney test). n = number of measurements at indicated locations, N = number of embryos, n was used for statistical analysis. c, Image of Cxcr4b-EGFP and membrane-tethered Kate2 expressed from the Cxcl12a sensor in the primordium. Image is a maximum-projection of a z-stack. Scale bar = 25 μm. d, Quantification of the Cxcr4b-EGFP/Kate2 ratio across the primordium. Mean (black line) and SD (gray lines) are shown. n = number of embryos. e, Illustrations and predictions for two models of tissue migration. f, Quantification of junction length (left) and the cumulative migration distance over time for three primordia. g, Trajectories of individual primordium cells (left) and frequency plots for angles between any two given cell velocity vectors (right). h, Localization of Cadherin-2-mCherry and membrane-tethered EGFP in the primordium (left). Cdh2-mCherry fluorescence intensity pseudo-colored as a temperature map (middle) and on the primordium’s rear at higher magnification (right). Images are single confocal slice from the z-stack. Scale bars = 25 μm (left) and 10 μm (right). i, Images of slices from a z-stack of 32 hpf TgBAC(cxcr4b:EGFP-CaaX) embryos stained for F-actin (left) or phospho-MLC (right) and GFP. Orthogonal views are shown.
