and mutations lead to differences in tissue overgrowth autonomy.

Genetic screens are used in to identify genes key in the regulation of organismal development and growth. These screens have defined signalling pathways necessary for tissue and organismal development, which are evolutionarily conserved across species, including . Here, we have used an FLP/FRT mosaic system to screen for conditional regulators of cell growth and cell division in the eye. The conditional nature of this screen utilizes a block in the apoptotic pathway to prohibit the mosaic mutant cells from dying via apoptosis. From this screen, we identified two different mutants that mapped to the Hedgehog signalling pathway. Previously, we described a novel mutation and here we add to the understanding of disrupting the Hh pathway with a novel allele of . Both of these Hh components are negative regulators of the pathway, yet they depict mutant differences in the type of overgrowth created. mutations lead to overgrowth consisting of almost entirely wild-type tissue (non-autonomous overgrowth), while the mutation results in tissue that is overgrown in both the mutant and wild-type clones (both autonomous and non-autonomous). These differences in tissue overgrowth are consistent in the eye and wing. The observed difference is correlated with different deregulation patterns of pMad, the downstream effector of DPP signalling. This finding provides insight into pathway-specific differences that help to better understand intricacies of developmental processes and human diseases that result from deregulated Hedgehog signalling, such as basal cell carcinoma.