fj reporter expression was compared in the wing and haltere discs. Expression is greatly reduced in the pouch of the haltere as compared to the pouch of the wing.

Enhancer trap staining is seen in concentric circles in leg discs from third instar larvae. At 4-6hrs after puparium formation, the disc has everted and the future tarsal segment boundaries are visible. A line of positive cells is seen adjacent to each tarsal furrow, with additional strong staining in the first tarsal segment and in the tibia. Weak expression in semicircular arcs is seen in the third instar antennal disc. Expression in the wing disc is concentrated in the prospective wing blade region. In eye discs, the strongest expression is observed in the central portion of the disc just anterior to the morphogenetic furrow, with no expression in the lateral portions of the disc. A gradient of expression is seen declining toward the posterior tip of the disc. In the larval brain, expression is concentrated in the outer optic anlage