The genetic interaction between ds and ft suggested that these two genes might function in the same pathway. A spontaneous mutation at the ds locus, ds1 was discovered in 1917 by Calvin Bridges. Dachsous and Fat differ from the classic cadherins, and from another cadherin protein of Drosophila, Shotgun , mainly due to the much larger number of extracellular cadherin domains in Ds and Fat. Based on the structures of Ds and Fat, and based on their genetic interaction, a model is presented which accounts for the physical interaction between Ds and Fat.
Flies mutant for dachsous exhibit a tissue polarity phenotype.
At least some of the tissue polarity phenotypes associated with ds resemble those seen in frizzled pathway mutants and seem unlikely to be due to an effect on cell adhesion. It has been known for some time that the function of ds relates to tissue polarity. Dachsous acts in the frizzled pathway where it affects signaling involved in the formation of proper wing hair polarity. The function of the frizzled pathway is essential for the formation of a wing with normal distally pointing hairs. This pathway is thought to be composed of both an intercellular signaling system and an intracellular signal transduction system.