Fig. 4. Over-expression studies in the wing. In a wild-type wing the large bristles are confined to the anterior wing margin (A) and hairs on the wing blade are uniformly organized pointing towards the distal parts of the wing (B). In fz wings the margin bristles show polarity defects (C) and a severe polarity disruption is evident in the wing blade hairs (D). Over-expression of UAS-Fz using the C765 Gal4 driver line phenocopies fz mutant wings. The margin bristles (E) and wing blade hairs (F) show clear polarity defects. Over-expression of Fz2 does not affect polarity but ectopic margin bristles occur (G,H), usually close to the margin but some can be in the main blade region (arrowheads). Over-expression of the two chimeras 2/1/1 and 1/2/2 induces ectopic margin bristles (I,K) and polarity defects (J,L).