Inhibition of protein palmitoylation yields a low amount of <i>Giardia</i> cysts.

<p>(A) Growth curves displaying optimal concentrations of 2-BP (left panel) or 2-FP (right panel) that do not affect <i>Giardia</i> growth. <i>Giardia</i> trophozoites were cultured with different concentrations of 2-BP (10, 20, 40, 50, 75 or 100 µM), 2-FP (100, 150 or 200 µM), or DMSO (control) for 48 h. The parasites were then analyzed by staining them with Trypan blue to distinguish live from dead cells and by counting them in a Neubauer chamber. The graph displays the number (mean ± SEM) of parasites counted in three independent experiments. (B) Percentage of encysting parasites and cysts after inhibition of protein palmitoylation. <i>Giardia</i> trophozoites were induced to encyst and 2-BP (10, 20 or 40 µM), 2-FP (100 uM) or DMSO (Control) added to the encysting media. After 48 h, the encysting parasites were stained with anti-CWP1 mAb and analyzed by fluorescence microscopy. One representative cell of each encystation state (encysting I, encysting II, cyst) is shown in the upper panel. The graph in the lower panel represents the percentage (mean + SEM) of the cells counted in each state in three independent experiments. The asterisks indicate significant difference compared with the control (Student's t test: * p<0.05; **p<0.01; ***p<0.001). (C) Number of nuclei in encysting II parasites treated with palmitoylation inhibitors. Trophozoites were induced to encyst and 2-BP (20 or 40 µM), 2-FP (100 µM) or DMSO (Control) added to the encystation media as described above. After 48 h, the encysting parasites were stained with anti-CWP1 mAb and DAPI, and analyzed by fluorescence microscopy. One representative encysting II cell is shown. Scale bars = 5 µm.