Targeting of cell ablation agents under the control of tissue-specific
promoters promises to be an important tool for studies of development
and function in higher organisms. Temperature-sensitive cell ablation
agents, recently developed for Drosophila, extend control to temporal
as well as spatial aspects of toxin expression. Here we discuss achie
vements to date, together with a novel form of enhancer trap technolog
y with the potential for driving toxin expression in a large range of
cell types.