The formation of complex structures from undifferentiated cells has always been a major question for developmental biologists. One good model to study the developmental processes that take part in organ formation is Drosophila melanogaster. In Drosophila, adult wings arise from larval imaginal discs: single-layered sheets of undifferentiated cells. Many signalling pathways play a role in wing formation, the Wingless (Wg) pathway among them. Wg is a secreted protein that binds to its receptor Frizzled at the receiving cells, activating the pathway that ultimately leads to the translocation of the -catenin Armadillo (Arm) to the nucleus, activating the targets of the pathway. Depleting Wg from the wing imaginal disc leads to adult flies without wings. On the contrary, Wg overexpression effects are level-dependant whereas mild levels cause overgrown wings, high levels cause smaller over-differentiated wings. Thus, the mechanisms by which Wg signalling orchestrates wing formation and the effects of Wg signalling in cell differentiation and growth have yet to be elucidated. In our work, we performed microarray analysis of three different conditions for Wg: depletion of Wg, Wg mild overexpression and overexpression of a constitutively activated Arm; in order to identify targets of the pathway for each condition. About 300 genes were differentially expressed in almost one of the conditions; transcription factors, adhesion-related and programmed cell death related-genes, among others. This analysis has been useful to find new targets of the pathway and to be one step closer to answer the question of how Wg regulates morphogenesis.

Trabajo presentado en el 23rd European Drosophila Research Congress (EDRC 2013), celebrado en Barcelona del 16 al 19 de octubre de 2013.

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