Fig. 10. Fluid-phase and GPI-AP uptake is unperturbed at restrictive temperatures in cells from mutant alleles of shi. Histogram shows the average amount of F-Dex (FDx; ±s.d.) internalized per cell in the indicated alleles and temperatures in an incubation period of 5 minutes. The similarity in uptake across all alleles, even at restrictive temperatures, demonstrates that mutations at the shi locus do not perturb the uptake of the fluid phase. Data shown are from three experiments each with at least 75 cells. (B,C) Hemocytes from shi^ts2;Collagen-Gal4;UAS-GFP-GPI animals were incubated with Fl-anti-GFP (green) at 31°C for 15 minutes in the presence of LR-Dex (B, red) or Cy5mBSA (C, red) prior to fixation and imaging on a wide-field microscope. Endocytosis of Fl-anti-GFP into LR-Dex (B, arrows)-containing endosomes is unaffected, whereas Cy5mBSA is blocked at the cell surface (C, small arrowheads). Insets (red, top; green, middle; merge, bottom) show the area marked by the asterisk. Bar, 5 µm; inset, 1 µm. (D) Model depicts the existence of dDyn-independent endocytic pathways for the fluid phase (yellow) and GPI-APs (green) in larval hemocytes. ALBR ligands (red) are endocytosed via clathrin and dDyn-dependent pathways into Rab5-positive early endosomes (EE), whereas the fluid phase (yellow) marks a separate Rab5-negative EE, before finally coming together in Rab7-positive late endosomes (LE).

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