Abstract
The tissue polarity genes in Drosophila are required to coordinate cell polarity within the plane of the epidermis. Evidence to date suggests that these genes may encode components of a novel signal transduction pathway. Three of the genes, frizzled (fz), dishevelled (dsh), and prickle (pk) share a similar tissue polarity phenotype, suggesting that they function together in a single process. dsh is also known to function as a mediator of wingless (wg) signaling in a variety of developmental patterning processes in the fly. In this study, we make use of a fz transgene and a hypomorphic fz allele as genetic tools in an attempt to order these genes in a genetic hierarchy. Our results argue that dsh encodes a dosage sensitive component required for fz function and that it likely acts downstream of fz in the generation of tissue polarity. Our findings suggest that dsh may have a general role in signal transduction, perhaps as a component of a receptor complex.
