Fig. 3. Dynamics of the contractile vacuole system revealed by VatM-GFP and interference reflection microscopy. An AX3 cell expressing VatM-GFP was viewed simultaneously by fluorescence microscopy (A-C) and IRM (D-F). These images correspond to frames 14 (A,D), 36 (B,E) and 51 (C,F) from Movie 1. Images were captured at 1 second intervals, and so these images span a total of 36 seconds. Three vacuoles in the upper right portion of the cell emptied during this time interval and were replaced by a tracery of tubules. The arrowhead marks the same position in each frame. Two other vacuoles (upper left) fused during this same interval and later emptied (see Movie 1).