Abstract
Transgenic regulators and reporter controls such as GAL80 and RNA interference (RNAi) constructs targeting fluorescent proteins are invaluable tools in Drosophila research. During experiments designed to temporally regulate gene expression, we observed unexpected flight defects in aged flies with constitutive expression of temperature-sensitive GAL80 (TS) . Furthermore, ubiquitous expression of RNAi targeting EGFP or mCherry induced survival and motor impairments, even in the absence of corresponding fluorescent reporters. These findings suggest that genetic tools commonly assumed to be physiologically inert can have measurable effects on motor behaviour. Researchers employing these tools should therefore interpret behavioural data with caution and include appropriate controls.