FIG. 9.

(A to C) Ultrathin cryosections of 15-h encysting cells, doubly immunolabeled with 8C5 (5-nm Au) and TSA 417 (10-nm Au). (A) 8C5 is localized to large encystation specific vesicles (esv), membrane cisternae (c), nuclear envelope, and peripheral vacuoles (pv) and is absent from the cell surface. TSA 417 is found in cisternae, peripheral vacuoles, and cell membrane (cm). The displacement of the ESV from the perinuclear cisternae is probably due to a sectioning artifact. (B and C) At 15 h, TSA 417 still dominates the cell surface and is also present in the peripheral vacuoles and cisternae. 8C5 is concentrated in the ESV, peripheral vacuoles, and cisternae and is just beginning to appear on the cell surface (arrowheads). Note that the external flagellum (f) cell is covered with membrane and TSA 417. Bars, 0.1 μm. Reprinted from reference 118 with permission of the publisher.