DWnt-4 and Wingless have distinct activities in the Drosophila dorsal epidermis

Wnt genes are often expressed in overlapping patterns, where they affect a wide array of developmental processes. To address the way in which various Wnt signals elicit distinct effects we compared the activities of two Wnt g enes in Drosophila, DWnt-4, and wingless. We show that these Wnt signals pr oduce distinct responses in cells of the dorsal embryonic epidermis. Wherea s wingless acts independently of hedgehog signaling in these cells, we show that DWnt-4 requires Hh to elicit its effects. We also show that expressio n of Wg signal transduction components does not mimic expression of DWnt-4, suggesting that DWnt-4 signaling proceeds through a distinct pathway. The dorsal epidermis may therefore be useful in the identification of novel Wnt signaling components.