Receptors for Wingless and other signalling molecules of the Wnt gene family have yet to be identified. We show here that cultured Drosophila cells transfected with a novel member of the frizzled gene family in Drosophila, Dfz2, respond to added Wingless protein by elevating the level of the Armadillo protein. Moreover, Wingless binds to Drosophila or human cells expressing Dfz2. These data demonstrate that Dfz2 functions as a Wingless receptor, and they imply, in general, that Frizzled proteins are receptors for the Wnt signalling molecules.

We thank Dr. Clark Riley, Ms. Carol Davenport, and Ms. Jani ne Ptak for synthetic oligonucleotides; Dr. Keith Fry for the gift of mAb ABS; Ms. Cathy Blizzard for cat eyes; Dr. Mark Molliver for donating fixed monkey eyes; Drs. Masafumi Tanaka and Wi nshi p Herr for Oct.1 cDNA; Mr. Hao Zhou for the GST-Ott-1 POU domain protein; Dr. Y.-W. Peng for rabbit retinas and Dr. Hua-Shun Li for chicken retinas; Dr. Elio Ravi ol a for advice on histologic techniques; and Drs. Robert Rodieck, Jen-Chi h Hsieh, and King-wai Yau for hel pful comments on the manuscript.