DORSAL-VENTRAL SIGNALING IN THE DROSOPHILA EYE

The development of the Drosophila eye has served as a model system for investigations of tissue patterning and cell-cell communication; howe ver, early eye development-has not been well understood. The results p resented here indicate that specialized cells are established along th e dorsal-ventral midline of the developing eye by Notch-mediated signa ling between dorsal and ventral cells, and that Notch activation at th e midline plays an essential role both in promoting the growth of the eye primordia and in regulating eye patterning. These observations imp ly that the developmental homology between Drosophila wings and verteb rate limbs extends to Drosophila eyes.