Fig. 1

Development of the ventral eye is affected by the L mutation. During development, the Drosophila eye field is confined by the activity of Wg. Establishment of the dorso-ventral boundary requires the activation of N. Concluded from genetic interactions, Lobe acts as a positive regulator of N and a negative regulator of Wg activities. Accordingly, L²/+ mutant flies display small eyes, where the ventral eye compartment is reduced at the expense of head epidermis. Arrows indicate positive, and bars negative interactions. Size bar, 100 μm