Figure 5. Dynamic expression of Dsulf1 in Hh producing and receiving cells during wing imaginal disc development.

(A-C) Temporal Dsulf1 expression in wing discs of early (A), mid (B) and late (C) wt 3^rd instar larvae. (A) Dsulf1 expression is detected at early 3^rd instar stage in groups of cells located in the central region as well as in anterior and posterior domains of the wing pouch. (B) At mid 3^rd instar stage, Dsulf1 expression domain in the central region of the wing pouch appears much broader. (C) At late 3^rd instar stage, a regionalisation of the Dsulf1-expressing domain was observed, defining stripes along the AP and DV axes reminiscent to provein domains (L1 to L5). Note a lower level of staining in the presumptive L3-L4 intervein region (asterisk). White arrowheads in C indicate Dsulf1 expression detected in the L2 and L5 provein domains. (D-H) Temporal expression of Col (D-F) and dppZ (G-I) in early (D, G), mid (E, H), and late (F, I) 3^rd instar larval wing discs. Note that Col and dpp expression domains extend from early (D,G) to mid (E,H) 3^rd instar larval stages. (F and insets in D and E) Double detections of Dsulf1 (red) and Col (green). In the wing pouch, Dsulf1 expression starts in the A compartment as assessed by comparison with Col expression (D, inset). From mid 3^rd instar larval stage, Dsulf1 expression is detected on each side of the Col-expressing domain, indicating that Dsulf1 is expressed both in A and P compartments (E, arrowheads in inset and F). (I) Comparison of Dsulf1 expression to dppZ at late 3^rd instar larval stage shows that the anterior stripe of high Dsulf1 expression in the A compartment overlaps the dpp expression domain (arrow) and that the posterior Dsulf1-expressing domain abuts the AP boundary (arrowhead).