MORPHOGENESIS OF DROSOPHILA PUPAL WINGS IN-VITRO

We have developed an in vitro culture system which supports the differ entiation of Drosophila pupal wings. Cultured wings develop marginal b ristles and wing veins, and wing cells form a single prehair at their distal vertex at the appropriate developmental stages. We have tested two molecules with well defined activities to determine the usefulness of this system for applying pharmacological approaches to wing differ entiation. Cycloheximide (CY) is a small molecule which inhibits prote in synthesis. We found that 50 nM CY rapidly blocks all stages of wing differentiation without lowering cell viability. Chitinase is an enzy me which cleaves chitin polymers and is involved in normal cuticle apo lysis. Chitinase applied prior to 28 h apf caused a contraction of the wing without affecting the general wing pattern. We have detected con nections between the epithelium and pupal cuticle that are presumably targets of chitinase and are necessary for maintaining normal tissue s hape during morphogenesis. Later in development exposure to chitinase caused a loss of normal prehair and bristle polarity, and high doses r esulted in a severe disruption of the actin cytoskeleton.