Detecting Stress Granules in Drosophila Neurons

Stress granules (SGs) are cytoplasmic ribonucleoprotein condensates that dynamically and reversibly assemble in response to stress. They are thought to contribute to the adaptive stress response by storing translationally inactive mRNAs as well as signaling molecules. Recent work has shown that SG composition and properties depend on both stress and cell types, and that neurons exhibit a complex SG proteome and a strong vulnerability to mutations in SG proteins. Drosophila has emerged as a powerful genetically tractable organism where to study the physiological regulation and functions of SGs in normal and pathological contexts. In this chapter, we describe a protocol enabling quantitative analysis of SG properties in both larval and adult Drosophila CNS samples. In this protocol, fluorescently tagged SGs are induced upon acute ex vivo stress or chronic in vivo stress, imaged at high-resolution via confocal microscopy and detected automatically, using a dedicated software.