mtv shapes the activity gradient of the Dpp morphogen through regulation of thickveins

Drosophila wings are patterned by a morphogen, Decapentaplegic (Dpp), a mem ber of the TGF beta superfamily, which is expressed along the anterior and posterior compartment boundary, The distribution and activity of Dpp signal ing is controlled in part by the level of expression of its major type I re ceptor, thickveins (tkv), The level of tkv is dynamically regulated by En a nd Hh. We have identified a novel gene, master of thickveins (mtv), which d ownregulates expression of tkv in response to Hh and En, mtv expression is controlled by En and Hh, and is complementary to tkv expression, In this re port, we demonstrate that mtv integrates the activities of En and Hh that s hape tkv expression pattern. Thus, mtv plays a key part of regulatory mecha nism that makes the activity gradient of the Dpp morphogen.