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. Author manuscript; available in PMC: 2017 Jun 20.
Published in final edited form as: Dev Cell. 2016 Jun 20;37(6):558–570. doi: 10.1016/j.devcel.2016.05.015

Figure 2. CG5278/stuck in traffic (sit) is a conserved fatty acid elongase homolog important for steroid production that affects cholesterol levels.

Figure 2

(A) Sit encodes a protein composed of 295 amino acids (aa) containing a conserved ELO domain similar to the human ELOVL7 fatty acid elongase protein. (B) Expression of sit is high in the ring gland (RG) compared to whole body (WB) 96 hours after egg laying (AEL). Knock down of sit expression specifically in the PG cells results in (C) delayed and impaired pupariation and (D) an increased pupal size. (E) RNAi knock down of sit in PG cells reduces ecdysone levels in the larvae during the L3 stage. (F) Lipid droplets detected by CARS microscopy in PG cells of L3 larvae with PG-specific RNAi silencing and in sit1D/2C mutants. (G) Co-localization of lipid droplets detected by CARS microscopy with NBD-cholesterol in the PG of animals with PG-specific silencing of sit. (H) L3 larvae with ubiquitous RNAi mediated silencing of Npc1a or sit contain higher levels of cholesterol. The RNAi effect was conditionally induced in L2 larvae 96 hours AEL by shifting larvae from 18°C to 29°C and assayed two days later. (I) Overexpression of an HA-tagged sit (sit-HA) in the PG rescues the developmental arrest phenotype caused by knock down of Npc1a. Day numbers refer to day AEL. Detailed description of genotypes is given in Supplemental Experimental Procedures. 20E; 20-hydroxyecdysone. Error bars indicate SEM (*P<0.05; **P<0.01; ***P<0.001). See also Figure S2 and S3.