Figure 3

Detection of caspase-like activity in the cytoplasm of P. berghei ookinetes. P. berghei ookinetes were subjected to a pancaspase CaspaTag assay, during which the fluorochrome inhibitor of caspases; FAM.VAD.fmk (green in A, C, D, E and F) or sulforhodamine conjugated caspase inhibitor; SR.DEVD.fmk (red in B) bound to activated caspase-like molecules. Cells with compromised cell membranes stain with propidium iodide (PI, orange). Ookinetes that show both caspase-like activity and membrane integrity are categorised as early apoptotic ookinetes (Green in A). Late apoptotic/dying ookinetes show caspase-like activity and loss of membrane integrity at the same time (C and D). Cells with compromised cell membranes, but no caspase activity were categorised as dead ookinetes (orange in E and F). F is a merged image of E, taken under bright field and FITC filter. Live ookinetes do not show caspase-like activity (see E and F). n: nucleus, de:dead, a:apoptotic, l:live.