Figure 1

TEM images of tegumental region of 5 week S. japonicum male. A, Tegument in transverse section showing the homogeneous outer third layer with flaps of cytoplasm containing only discoid bodies (DB) and a central pitted region with a characteristic channel network (white arrows) as well as vesicles, whilst basal invaginations (BI) are evident in the innermost layer (M, muscle layer). B, Tegument cell body showing that two types of vesicle, dark bodies (DKBs) and discoid bodies, are manufactured here. C, Cytoplasmic connection between tegument cell body and tegument surface, with dark body and discoid body in transit. D, Dark bodies in tegument cell bodies reveal different profiles, e.g. top view (starred) and side view (arrowed). E, Dark body in tegument, docking via its opaque sphere to the end of a channel, so releasing its cargo. Scale bar: A 1 μm; B 1 μm; C 500 nm; D 200 nm; E 200 nm.