Journal: Nature Communications

Article Title: Periodic formation of epithelial somites from human pluripotent stem cells

doi: 10.1038/s41467-022-29967-1

Figure Lengend Snippet: a, b Time-lapse images of the HES7 promoter-luciferase reporter activity in a representative somitoid. The starting point on day 4 was defined as time 0. See also Supplementary Movie . Scale bars: 500 µm. Images were taken by an LV200 luminescent microscope. b Enlarged images of several time points are also shown. Arrows indicate the somite boundaries. BF: Bright field. c Kymograph of the HES7 reporter activity measured along the posterior-anterior axis (the white arrow) of the same sample shown in a , b . d Detrended intensity (top) and the oscillation phase (bottom) of the HES7 reporter activity in the same sample shown in a , b . Blue and orange lines indicate the signals measured in the posterior and anterior regions of somitoids, respectively, marked in c . The gaps in the graph correspond to short halts of imaging to adjust the sample position. N = 14 samples showed similar oscillatory patterns. e Relationship between HES7 oscillations and segmentation timings. Detrended HES7 reporter activity of the entire image of the same sample shown in a and b. Arrows indicate the timings of somite formation, and the colors correspond to the arrows in b . f Periods calculated from the HES7 oscillations and somite formation. Mean ± SEM. Each point in the graph indicates an average period of several oscillation peaks or somite formation timings in one sample from day 5 to day 6. N = 14 (HES7 oscillation) and 17 (Somite formation). 5 independent experiments. P -value is from two-sided student’s t-test. Source data are provided as a Source Data file.

Article Snippet: Live-luminescence imaging was performed with an LV200 luminescent microscope (Olympus, cellSens Dimension software) using a 10x objective lens (UPLXAPO10X).

Techniques: Luciferase, Activity Assay, Microscopy, Imaging