Movie S1.

The 3D pseudoislet microstructure as revealed by light-sheet microscopy. Shown is a 3D rendering of a pseudoislet acquired on a Lightsheet Z.1 microscope (Zeiss). αTC1-6 cells (glucagon+; blue) position in the mantle whereas INS-1E cells (insulin+; green) are localized to the core of the cell aggregate. Hoechst 33342 was used as nuclear counterstain (pseudocolored in red). (Scale bar: 30 μm.)