Table 1. Main advantages and disadvantages of the most common drug-inducible gene expression systems currently available to the Drosophila community.

Expression system	Reference	Advantages	Disadvantages
GeneSwitch	Osterwalder et al., 2001	Non-toxic for adult flies	Not compatible with existing GAL4 linesLeaky expression (Poirier et al., 2008; Scialo et al., 2016)Larval exposure impacts on adult sleep patterns (Li and Stavropoulos, 2016)Drug is unsafe to handle for female researchersDrug is expensive
QF System	Potter et al., 2010	Non-toxic for flies	Not compatible with existing GAL4 lines
Tet-off GAL80	Barwell et al., 2017	GAL4/UAS compatible	Long induction time (>5 days)Requires x2 copies of the GAL80 transgeneAffects microbiota
TMP INDUCIBLE	Kogenaru and Isalan, 2018; Sethi and Wang, 2017	GAL4/UAS compatible	Currently not compatible for general use with existing GAL4 linesTMP drug is only dissolvable in DMSO (affects survival of larvae) or has to be added as a dry powder to food