Figure 2. Blocking endocytosis affects actin organization, but not DE-Cadherin levels.

Confocal sections from Drosophila embryos immunostained with DE-Cadherin (A–L) and phalloidin to visualize F-actin (A'–L'). (A–C'). Wild type embryos during different DC stages show the dynamic distribution of DE-Cadherin and F-actin. Arrowheads in inset B highlight the clearance of DE-Cadherin from the LE and accumulation at the ANCs. In this and all subsequent genotypes three different stages of DC are shown (D–F'). Early stages of DC embryos expressing Rab5^DN ubiquitously show irregular AS cell shapes (D, green contours) and big lamellipodia (D', yellow arrowhead). Later during DC, these embryos exhibit impaired epidermal elongation and puckering (E, yellow arrow) and a strong actin cable with bigger and more filopodia (E', green arrowheads). Actin projections are also observed throughout the epidermis (E', red arrowheads). Zippering is impaired in these embryos (F, F'). (G–I') Embryos expressing Rab5^DN in the AS results in changes in cell morphology, particularly evident at early and late stages of DC (G,I), but epidermal cell elongation is not compromised (H). Zippering is also affected (I). Abnormal filopodia and lamellipodia are observed in the AS (G', I', yellow arrowheads) throughout DC. Embryos expressing Rab5^DN in the engrailed domain do not exhibit defects in epidermal cell elongation nor in zippering. DE-Cadherin shows a wild type distribution (J–L), but stronger levels of Actin are observed in the engrailed domain (J', K'). Rab5^DN domain of expression is enclosed in the yellow dashed line (J–L').