Embryonic expression of dSTIM. Whole mount in situ RNA hybridization (A-K) and immunofluorescence (L-Q) to detect dSTIM expression at key developmental stages of wild-type Drosophila embryogenesis. All embryos are shown with the anterior end to the left, with lateral view shown for all stages 1–12 (A-I, L-O), lateral, ventral and dorsal views for stage 13 (J-K), and ventral view for stage 15 (P, Q). Embryos are staged according to Hartenstein (1993). A) Stage 1 post-fertilisation. B) Stage 4 and C) Stage 5 of cellularisation, arrow indicating pole cells. D) Stage 7 invaginating germ layer. E) Stage 8, and F) Stage 9, showing anterior (a) and posterior (p) midgut primordia. G) Stage 11, beginning of germ-band retraction. H) Stage 12, late midgut fusion. I) Stage 13, lateral view showing malphigian tubules (mt). J) Stage 13, ventral view, showing clusters of dSTIM positive cells along the ventral midline (arrow), seen at higher magnification in J' (arrow). K) Stage 13, dorsal view showing salivary glands (s). L) Stage 5 blastoderm, showing apical capping of dSTIM protein, association of dSTIM with lateral cell membranes (M, N), and presence of dSTIM in pole cells (arrow) (O). P) Stage 15, showing dSTIM localization in clusters of CNS cells along the ventral midline (arrow) and salivary glands (s) (Q).