Rab11 is essential for lgl mediated JNK-Dpp signaling in dorsal closure and epithelial morphogenesis in Drosophila

Dorsal closure in Drosophila provides a robust genetic platform providing deep insights into the basic cellular mechanisms that govern epithelial wound healing and morphogenesis. As dorsal closure proceeds, the adjacent epithelia advance contra-laterally involving coordinated cell shape changes in order to successfully accomplish the process. The JNK-Dpp signaling in these cells plays an instrumental role in guiding their fate as gastrulation completes. A huge number of genes have been reported to be involved in the regulation of this core signaling pathway, yet the mechanisms by which they do so is hitherto unclear, which forms the objective of our present study. Here we show that lgl, which is a potent tumour suppressor gene, conserved across the phyla till humans, regulates the JNK-Dpp pathway in the dorsal closure and epithelial morphogenesis process where in ectopic knockdown of this gene results in the failure of dorsal closure. Interestingly, we also find Rab11 to be interacting with lgl as they together regulate the core JNK-Dpp signaling pathway during dorsal closure and also during pupal thorax closure process. Using the robust Gal4-UAS system of targeted gene expression, we show here that Rab11 and lgl synergize to successfully execute the dorsal closure and the similar thorax closure process, ensuring proper spatio-temporal JNK-Dpp signaling.