(d) Persistence of Venus::HES5 in 20μm regions expressed as continuous time intervals when signal in the band is high or low compared to its mean (see Methods); individual datapoints (gray) indicate quantification of high and low persistence time obtained from over 300 thin bands collected from multiple tissues with 2 z-stacks per tissue and 2 repeats (left and right of ventricle) per z-stack; dots indicate paired medians of 5 independent experiments; statistical test is paired t test of median per experiment with two tail significance and p=0.7171. 