Absence of Ags1 results in a defective final cell separation step. (A) Ags1-depleted cells stay attached through the septum edging for a long time, even after disappearance of the remaining CW-stained primary septum. Cells were grown as in Fig. 8 A. Circle: side-contact region with different amounts of CW-stained primary septum. Bar, 5 µm. (B) The Ags1-depleted sister cells remain attached by their septum edging (arrowhead) for at least two cell cycles. Cells were grown in EMM+T+S for 4 h. Arrowhead: side-contact region. Broken arrow: movement of the attached cells. Square: magnified area. Elapsed time is shown in minutes. Bars, 5 µm. (C) Ultrastructure of Ags1-depleted cells attached by the septum edging (arrow). The cells display irregular walls with cavities (open arrowhead) and attached wall fragments (closed arrowhead) at the pole lateral region. Cells grown as in Fig. 6 A were analyzed by TEM (top) or scanning electron microscopy (SEM, bottom). Bars, 1 µm.