Autophagic programmed cell death in Drosophila.

Autophagic programmed cell death occurs during the development of diverse animal groups, but the mechanisms that control this genetically regulated form of cell killing are poorly understood. Genetic studies of bulk protein degradation in yeast have provided important advances in our understanding of autophagy, and recent investigations of Drosophila autophagic cell death suggest that some of these mechanisms may be conserved. In Drosophila, several steroid-regulated genes that encode transcription regulators are required for autophagic cell death. These transcription regulators appear to activate a large number of genes that play a more direct role in cell killing, including genes that function in apoptosis such as caspases. While caspase function is required for autophagic cell death during Drosophila development, genes encoding proteins that are similar to the yeast autophagy regulators are also induced in dying salivary glands. Furthermore, numerous noncaspase proteases, cytoplasmic organizing factors, signaling molecules, and unknown factors are expressed in interesting patterns during autophagic cell death. This article reviews the current knowledge of the regulation of autophagic programmed cell death during development of Drosophila.