Evolution along Earth history has developed a great number of different organisms with a consequent incredibly variety of forms and sizes. One of the big questions in Biology is to understand which genes and what kind of changes in their sequences are responsible for the evolution of the mentioned morphological diversity. Using Drosophila melanogaster and Tribolium castaneum as organism models, the aim of our lab is to elucidate the mechanisms that allow the formation of new morphologies and sizes. We use two different organ models to address these questions: the tracheal system and the imaginal wing disc. In both systems, Wnt signalling plays a crucial role during its respective development controlling morphogenesis and size. For instance, we have found that small changes in Wnt signalling activation result in a different final size of the Drosophila wing.

This could mean that small changes in the domain of activation of a signalling pathway in a tissue could give rise to different organ size along evolution. This effect could be achieved by either acquisition of new regulatory regions of target genes or by changes in the regulation of the activity of the pathway. Therefore, identification of new target genes of the pathway and the comparison of their expression pattern in Drosophila and Tribolium, in trachea and wing disc, will give us information of how this signalling pathway has evolved to control pattern as well as organ size along evolution.