Movie S1.

Combined bioluminescence-fluorescence time-lapse microscopy of human pancreatic islets from ND donors. Human α- and β-cells were labeled with adenovirus carrying Pppg-mCherry construct (red labeling) or with RIP-GFP lentiviruses (green) respectively, and with the Per2-luc bioluminescence reporter (blue) (see also Fig. 2A-B). Bioluminescence signal was measured over α- and β-cells within the area encircled in yellow. Representative trajectories are traced in the colors of rainbow over the image, illustrating the movement of the traced cell between the first time-lapse image traced in red, through the entire set of images acquired every hour until the last image traced in blue. Islets were synchronized by a 1 h forskolin pulse (time point 0), and subsequently subjected to bioluminescence-fluorescence time-lapse microscopy for at least 70 h. Upper left video shows bioluminescence acquisition; upper right video is a merge of bioluminescence channel (blue), green fluorescence channel (RIP-GFP expression), and red fluorescence channel (Pppg-mCherry expression). Lower videos represent a close-up of one islet from the corresponding upper videos (the enlarged area is indicated with the blue square on the video).