Movie S2

The polarization of the tight junction protein, ZO-1, during neural rosette formation.
Human embryonic stem cells were driven towards neural lineage, during which process neural stem cells appeared at 4-day differentiation and neural rosettes formed at 9 days of differentiation. Cells were fixed and stained with ZO-1 antibody (green) and DAPI (blue) at 7-day differentiation, when neural rosettes were starting to take shape. The 3-D animation was generated from one of the Z-stack images taken from 7 days of differentiation using Black Zen software (Zeiss). The movie shows that the location of ZO-1 in the tight junction (see Movie S1) is breaking down and the protein relocates to the apical region of neural rosettes. The directions of the X,Y, and Z axes are indicated on the bottom left.