Microtubule inhibitors block the morphological changes induced inDrosophila blood cells by a parasitoid wasp factor

Summary The shape change ofDrosophila melanogaster blood cells (lamellocytes) from discoidal to bipolar that is caused by a factor from the female parasitoidLeptopilina heterotoma is blocked by the tubulin inhibitors vinblastine and vincristine in vitro. The actin inhibitor, cytochalasin B, causes arborization ofDrosophila lamellocytes and acts synergistically with the wasp factor to alter lamellocyte morphology. Lamellocyte arborization induced by cytochalasin B is blocked by simultaneous treatment with vinblastine. These observations indicate that the changes in lamellocyte shape induced by both the wasp factor and cytochalasin B require microtubule assembly.