Abi colocalizes with Dlar at tricellular contacts. (A–F) Confocal images from the basal surface of developing wild-type (WT) and dlar (dlar13.3/dlar5.5) mutant egg chambers stained for endogenous Dlar, endogenous Abi, and F-actin (phalloidin). Stages are indicated. Bars, 5 µm. The arrowheads mark tricellular contacts where Dlar and Abi overlap. Note that in dlar mutant cells, endogenous Abi and F-actin can be still detected at tricellular contacts (B, D, and F, arrowheads), but overall, the signal intensity is clearly reduced.