Figure 5.

Transmission electron micrograph of the periphery of a pericardial cell isolated from a wild-type third instar larva. The cortex of pericardial cells is characterized by invaginations of the plasma membrane, forming a labyrinth-like channel system with a considerably increased surface area. Endocytosis takes places at the terminal sites of the channel system. Such an event is visible at the labeled channel on the right. Abbreviations: bm, basement membrane; pm, plasma membrane; ch, labyrinth channel; cv, coated vesicle; slit diaphragms are indicated by circles.