RNAi effectively knocks down dSTIM in wing imaginal discs. Whole mount in situ RNA hybridization (A-C) and immunofluorescence (D-F) to detect dSTIM expression in 3rd instar wild-type wing (A, B, D, E) and wing discs expressing dSTIMRNAiinduced by en.Gal4 (C, F). Discs are presented with anterior end to the left and dorsal end at the top. Hybridisation with the anti-sense RNA probe shows uniform expression of dSTIM transcripts in the wing disc (A). Hybridisation with the sense probe shows negligible staining throughout the wing discs, except for trapping of probe in tissue folds (B). dSTIM protein (green) is uniformly expressed both apically (D) and basally (E) in cells of the wing disc, in contrast to Arm (red) which is mainly apically localized (D, E). Expression of dSTIMRNAidriven by en.Gal4 results in a marked reduction in transcript (C) and protein (F) levels confined to the posterior region of the wing disc.