Figure 1.

Wild-type expression patterns for Cubitus interruptus, Engrailed, Collier and Hedgehog. Ci in red (c and d), En in blue (c, d, f and i), Col in red (f) Hh in green (i). a. Ci expression; purple line denotes antero-posterior boundary. b. En expression. c. Merge of a and b. d. Enlargement of region equivalent to that boxed in c. Note the overlap between cells expressing En (blue) and Ci (red) at the antero-posterior boundary. e. Collier expression. f. Higher power image showing Col and En. Note the slight overlap at the A/P boundary. g. Hh expression in the wing pouch h. En expression. i. Merge of g and h. It can be seen that there are cells that express En (blue) which do not express Hh (green).