Fig. 4. dSyx16 is a membrane protein expressed ubiquitously in Drosophila. Embryos after deposition (AED) were collected and allowed to develop for indicated period of time (A). Larvae, pupae, adults were collected and imaginal discs were dissected from third instar larvae (B). All samples were lysed in SDS-homogenization buffer and subject to SDS-PAGE and western blot analysis. In C, crude membrane fraction from homogenized Oregon R adults was treated with H₂O, KCl, Na₂CO₃, Urea, Triton X-100 or SDS and then centrifuged to separate the soluble from the insoluble. All samples were re-suspended to the same volume before subjecting them to SDS-PAGE and western blot analysis.