Figure 7. Composition and distribution of endosomal compartments during terminal cell growth.

• A–D
  High time resolution imaging of the membrane marker CD4::mIFP expressed under btl‐gal4. (A) Example of a large CD4 vesicle (arrowhead) rapidly moving towards the tip of the terminal cell. (B–D) Analysis of 28 CD4 vesicles in five terminal cells. (B) Trajectories of CD4 vesicles with their original position mapped to the origin of the plot. (C) Rose diagram of the trajectories shown in (B). (D) Speed of CD4 vesicles compared to speed of tube growth measured over 25 min. Data are plotted as mean ± SD. *P < 0.001, Mann–Whitney U‐test.
• E–H
  Terminal cells expressing the membrane reporter CD4::mIFP together with markers for vesicles of the endocytic pathway. (E) Rab5::YFP, red arrowheads point to a Rab5‐positive vesicle; the white arrowhead shows the same vesicle once it lost the Rab5 signal. (F) FYVE::GFP, a PI₃P reporter; and Spin::mRFP, a lysosomal marker. Black arrowheads point to small FYVE::GFP vesicles, and the squared area shows large ones at the tip. (G) Par6::mCherry and endogenously labelled Rab7::YFP. (H) Percentage of CD4::mIFP vesicles that carry the indicated markers. Data are plotted as mean ± SD. For each marker, we analysed at least 20 min of cell growth with 10–20 time points. Number of cells analysed: Par3, n = 2; Rab5, n = 3; FYVE::GFP, n = 4; FYVE::GFP‐Spin::RFP (which includes single‐ and double‐positive vesicles), n = 3; dLamp1, n = 2; Rab7, n = 5.

Data information: Scale bars: 5 μm.Source data are available online for this figure.