AceTree main control and ImageWindow. The image window shows the annotated data for the four-cell stage embryo at the first time point of the series. The main control shows the JTree representation with cell ABa highlighted. The four founder cells, ABa, ABp, EMS, P2 can be seen in both the image window and the tree view. The tree also shows that a polar body has been found at this time point, called polar1. However it is not visible in plane 17, the plane shown in the image window.