Lpp and LTP function together to mobilize lipids from the gut.
(A) Immunofluorescence of a second instar larval gut, stained for Lpp, LTP and neutral lipid droplets. Lpp, LTP and lipid droplets are enriched in the same subsets of the anterior and posterior midgut. (*) indicates a nearby piece of fat body. GC: gastric caeca; AM: anterior midgut; PM: posterior midgut; HG: hindgut; MT: malpighian tubule. Scale bars = 200 µm. (B) Lipid droplets of guts from first instar wild-type and mtpΔex1 larvae, visualized with Nile red. Loss of MTP causes strong neutral lipid accumulation. Yellow: neutral lipids; red: phospholipids. GC: gastric caeca; AM: anterior midgut; PM: posterior midgut; HG: hindgut. Scale bars = 200 µm. Scale bars blow ups = 20 µm. (C) Lipid droplets of posterior midguts upon MTP, LTP or Lpp RNAi, visualized with Nile red. Knock-down of either protein causes similar accumulation of neutral lipid. Scale bars = 50 µm.