Tango1 knockdown impairs general secretion in fat body cells. (A) Confocal images of fat body cells from wild-type (top) and Tango1 knockdown (BM-40-SPARC-GAL4 > UAS-Tango1i, bottom) third-instar larvae (L3 stage) showing distribution of Collagen IV chains α2 (Vkg.GFP, left) and α1 (anti-Cg25C, right). Nuclei were stained with DAPI. (B) Electron micrograph of Cg>Tango1i fat body. Asterisks mark cargo-filled dilated ER. LD, lipid droplets. (C) Distribution of Collagen IV (Vkg.GFP) in wild-type, BM-40-SPARC>PH4αEFBi, >Tango1i, and double >PH4αEFBi+Tango1i larvae. Insets magnified in the bottom panels show Vkg.GFP localization to muscle basement membranes (wild type) or diffuse blood signal (PH4αEFBi). (D) Wild-type (top) and Tango1i (bottom) fat body cells expressing RFP coupled to signal peptides of Vkg (Cg>SPVkg.RFP, left) and Cg25C (Cg>SPCg25C.RFP, right). (E) Wild-type and Tango1i fat body cells showing distribution of Rfabg (Apo-B, Rfabg.sGFPfTRG.900), YFP-tagged Trol (Perlecan, trolCPTI-002049.YFP), Nidogen (anti-Ndg staining), Fat-spondin (fat-spondinCPTI001685.YFP), and Ferritin (Fer1HCHG188.GFP). (F) Wild-type and Tango1i fat body cells expressing secr.GFP (BM-40-SPARC>secr.GFP, signal peptide of Wingless coupled to GFP).