In Drosophila, the Pygopus gene is a key mediator of canonical Wnt signaling. In one study, 12 distinct measures of Wnt signaling in Pygo mutants were performed, including analysis of leg, wing, and eye imaginal discs. In 2 cases there was a significant reduction of Wnt signaling and in 10 cases a complete block [10]. A second study in Drosophila examined the effects of Pygo mutation on cuticle patterning, midgut constriction, central nervous system, and cardiac development, and concluded that "Pygo is an essential component in the Wg signal transduction pathway". [8].