Fig. 3

Fig. 3 An amplitude threshold of oscillations is required for successful segmentation in a genetic background displaying variable expressivity.

a–c Brightfield images of her1^ci301;her7^hu2526;her1-Venus^+/-;her7-Venus^+/- embryos with variable expressivity. Representative embryos are ordered by their increasing number of defective somites (a–c). Stars show defected boundaries between 11th and 25th somite boundaries. d Number of defected boundaries per one side of each embryo (n = 41, N = 3). Black lines show median (thick), and quartiles (thin). e Brightfield and Venus images of a single embryo at 70, 150, and 440 min. Yellow, red and green lines show line-of-interest (LOI) borders in Venus channel at each time point. Star shows a defected boundary. f A representative kymograph of Venus signal seen in (e) between 7 and 25 somite stages (for 600 min, y-axis) along the entire PSM (x-axis, posterior-aligned to the left). Blue solid line shows determination front position. Star shows where and when the 15th boundary (defected) is determined, and white dash shows when it is formed. g Smoothened line profile of Venus signal along determination front position (arbitrary units, arb. units). Blue star shows the wave determining the defected boundary. h Normalized amplitude of waves for intact (striped, n = 283, N = 3) and defected (dotted, n = 328, N = 3) boundaries. ****P = 0.4908 × 10⁻⁸, two-tailed Mann–Whitney U-test. The whisker plot shows the median (line), quartiles (box), as well as the 10th and 90th percentiles (whiskers). n is the number of embryos in (d), and boundaries in (h); N is the number of independent experiments. Scale bars are 200 µm. Source data are provided as a Source Data file.