Skip to main content
. 2020 Oct 5;21(11):e50944. doi: 10.15252/embr.202050944

Figure 1. Epiblast cells organize as rosettes at the onset of primitive streak morphogenesis.

Figure 1

  • A
    Manually segmented rosettes on 3D reconstructions from Z‐stacks of 25 μm of an E5.75 embryo imaged using lightsheet microscopy. AVE cells are in green, and all cell membranes are labelled in grey. Left: anterior view; middle: lateral view (anterior to the left); right: posterior view. Scale bars: 20 μm. (A′) Mouse line strategy used to perform live imaging. (A″) Left: number of rosettes normalized by the total number of cells in the epiblast region in focus expressed in percentage. Right: frequency of rosettes, normalized by the area in mm2 of the epiblast region in focus and the time of observation in minutes. Data information: Mean ± SEM, n = 41 frames from three embryos. Normality was assessed using a Shapiro–Wilk test, followed by Kruskal–Wallis and non‐parametric Mann–Whitney tests. **P‐value ≤ 0.01, ***P‐value ≤ 0.001.
  • B, C
    Rosettes outline on optical slices from E5.75 (B) and E6.25 (C) embryos imaged by confocal microscopy. AVE cells are in green, and all cell membranes are labelled in grey. Left: anterior view; middle: lateral view (anterior to the left); right: posterior view. Scale bars: 20 μm. (B′) Mouse line strategy used to perform live imaging. (B″, C′) Left: Number of rosettes normalized by the total number of cells expressed in percentage. Right: density of rosettes, normalized by the area in mm2 of the epiblast region in focus. The posterior region includes the PS region, as it could not be precisely discriminated. Data information: Mean ± SEM. E5.75: n anterior = 19 frames from three embryos, n lateral = 23 frames from five embryos, n posterior = 20 frames from three embryos. E6.25: n anterior = 16 frames from two embryos, n lateral = 12 frames from one embryo and n posterior = 16 frames from two embryos. Normality was assessed using a Shapiro–Wilk test, followed by Kruskal–Wallis and non‐parametric Mann–Whitney tests. ns, non‐significant, *P‐value ≤ 0.05, **P‐value ≤ 0.01 and ***P‐value ≤ 0.001.

Source data are available online for this figure.