Figure 7
GFP-LD fusion protein localizes to lipid droplets in many types of cells. The intracellular distribution of GFP-LD was examined in animals expressing GFP-LD in the female germ line (A, B, C: matα4-Gal4-VP16 driver) or in somatic cells (D, E, F: Act5C-Gal4 driver). Colocalization with Nile Red signal (A, B, D, E, F) or enrichment in the lipid-droplet layer after centrifugation (C) indicates that GFP-LD is associated with lipid droplets. (A) Stage 13 oocyte. (B) Stage 10 nurse cells. (C) Egg chamber after centrifugation. Bright-field microscopy (BF) reveals distinct layering. Prominent brown lipid-droplet layers are evident in the nurse cells (left) and the oocyte (right); the oocyte also shows a gray yolk layer. GFP-LD is enriched in the droplet layers of both nurse cells and oocyte. The merged image also shows yolk autofluoresence in blue. (D) Follicle cells. (E) Larval salivary gland. (F) Wing imaginal disc. In all cases, the intensity of GFP-LD signal varies dramatically between lipid droplets. GFP-LD signal was also present, at lower levels, elsewhere in the cell (e.g., E). Scale bars = 5 μm.