Fig. 7. A model for the role of brush-border spectrin in the recycling pathway. Newly formed endocytic vesicles must navigate through the F-actin rootlets (gray vertical bars), spectrin (thin black filaments) and myosin II (thick black strands) in the terminal web before proceeding to the early endosome (EE), where a decision is made either to return the protein to the membrane (recycle, 1) or to follow the degradation pathway (lysosome, 2). Our data suggest that brush border spectrin `primes' proteins on vesicles in the terminal web (P) in a way that influences the decision to recycle or degrade them at the early endosome. In ß_H-spectrin mutants, we suggest that diversion of membrane flow along pathway 2 results in the run down of the early endosome system at the start of the third instar and the concomitant increase in lysosomal compartments that we observe.