REGULATORY CONTROL OF SIGNAL-TRANSDUCTION DURING MORPHOGENESIS IN DROSOPHILA

Morphogenesis shapes pattern and size during development. The initiati on and propagation of morphogenetic processes is led by the integrated activation of signaling cascades. Much is known about regulatory cont rol of signaling cascades in cell culture systems. However, how this r egulatory elements act when cells need to behave coordinately is still unknown territory. The morphogenetic process of dorsal closure procee ds through changes in cell shape and polarity under the control of JNK signaling. Amongst other regulatory elements, Puckered, a Drosophila MARK phosphatase, is involved in a negative feedback loop that control s JNK signaling activity. puckered is expressed in many other tissues, could influence other developmental events and might regulate differe nt signaling cascades. The negative regulatory control of signal trans duction pathways could be a general mechanism regulating differentiati on and morphogenesis.