Fig. 2

Her6 expression is heterogeneous across the telencephalon in HV embryos. (A) Schematic of 20 hpf embryo, dashed red line indicates the position of live imaging (left). Transverse view of 3D-reconstructed confocal live images (right) from 20 hpf telencephalon of HV embryo showing HV (yellow) and H2B-mKeima (blue). Dashed contour indicates the telencephalon boundaries. (B) Coefficient of variation (CV) at population level for HV and H2B-mKeima in HV embryos at 20-26 hpf. Boxplots indicate median with interquartile range; dots represent average CV per time point per embryo. (C) 3D-reconstructed snapshot confocal images depicting a single cell expressing HV over time, starting at 20 hpf. (D) HV expression over time of the single cell marked in C. The arrows indicate the time points of snapshots shown in C. The graph also depicts dynamic parameters including intensity mean of a single cell over time (blue dashed line), relative trend (green arrow) and fold-change (red circles). On x-axis 0=20 hpf. (E) Boxplots comparing the CV for each cell trace over time between HV and H2B-mKeima time-series from the same cell. Boxplots indicate median with interquartile range (IQR), whiskers indicate maximum (maximum value in the data, Q3 +1.5× IQR) and minimum (minimum value in the data, Q1 + 1.5× IQR) points, dots represent outliers. (F) Comparison of relative trend between HV and H2B-mKeima obtained from the same cell trace. Values >1 indicate upregulation, values=1 indicate steady expression and values <1 indicate downregulation. Bars indicate median with interquartile range, circles represent cells. (G) Representative examples of oscillatory and non-oscillatory HV time-series (i) with corresponding H2B-mKeima traces (ii) obtained from the same nuclei. Corresponding HV traces after being divided by H2B-mKeima (iii, HV/H2B normalised). Normalised traces after removing the long-term trend (iv, HV/H2B detrended). (H) Comparison of peak-to-trough fold-change in HV/H2B (Her6:Venus/H2B-mKeima) versus H2B (H2B-mKeima) collected in the same nuclei. Bars indicate median and interquartile range; each dot is median per embryo. (I) Aggregate power spectral density (PSD) obtained from time-series HV, HV/H2B and nuclear control H2B-mKeima from one experiment. (J) Percentage of oscillators in detrended HV/H2B versus H2B control. Bars indicate median, each dot indicates median per embryo. (K,L) HV period and peak-to-trough fold-change from HV/H2B detrended single cells. Bars indicate median and interquartile range, dots indicate cells. *P≤0.05; **P≤0.01; ****P≤0.0001 (statistical test details found in Table S6). Scale bars: 20 µm (A); 5 µm (C).