Neuropeptide T2A-GAL4 knock-ins illustrate practical considerations for interpreting GAL4 reporter patterns in Drosophila
Year: 2026
Type: preprint
Abstract: Transgenic GAL4 lines are widely used in Drosophila to label and manipulate specific cell types, but the resulting reporter expression patterns do not always represent ongoing driver activity. We generated a collection of neuropeptide T2A-GAL4 knock-ins and characterized their expression by native-fluorescence imaging using UAS-CD8::GFP and a brp-miRFP680 knock-in, eliminating the need for immunostaining. During characterization, we observed both timing-dependent changes in adult GFP labeling and GAL4-associated cellular abnormalities. Using temperature-sensitive GAL80, we found that adult GFP labeling in certain neurons driven by CCHa2-T2A-GAL4 and Dsk-T2A-GAL4 depended on GAL4 activity before eclosion and was not reproduced by adult-restricted induction. Several GAL4 lines also showed dominant developmental phenotypes. Heterozygous Burs-T2A-GAL4 animals, for example, displayed wing expansion defects that were fully suppressed by GAL80. Severe wing defects were not accompanied by a reduction in the number of reporter-labeled neurons before eclosion, but the morphology of these neurons was affected. These observations illustrate how developmental driver history and GAL4-associated cellular effects can influence reporter patterns in the adult nervous system.
Institutions: Tokyo University of Science, Tohoku University
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7214049860