Differential efficacy of genetically swapping GAL4

Abstract

Several large or mid-scale collections of Drosophila enhancer traps have been recently created to allow for genetic swapping of GAL4 coding sequences to versatile transcription activators or suppressors such as LexA, QF, split-GAL4 (GAL4-AD and GAL4-DBD), GAL80 and QS. Yet a systematic analysis of the feasibility and reproducibility of these tools is lacking. Here we focused on InSITE GAL4 drivers that specifically label different subpopulations of olfactory neurons, particularly local interneurons (LNs), and genetically swapped the GAL4 domain for LexA, GAL80 or QF at the same locus. We found that the major utility-limiting factor for these genetic swaps is that many do not fully reproduce the original GAL4 expression patterns. Different donors exhibit distinct efficacies for reproducing original GAL4 expression patterns. The successfully swapped lines reported here will serve as valuable reagents and expand the genetic toolkits of Drosophila olfactory circuit research.

Keywords:

• Genetic swapping
• InSITE
• GAL4
• LexA
• QF
• GAL80
• interneuron
• olfactory system

Acknowledgments

We thank Thomas Clandinin (Stanford U.) for providing InSITE enhancer trap lines and donor fly stock. We thank Marcus Calkins for invaluable comments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability

The authors declare that all data supporting the findings of this study are available within the article and its supplementary information files, or from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported by MOST grants (101–2311-B-001–016-MY3 and 104–2311-B-001–033-MY3) (Ministry of Science and Technology, Taiwan) to Y.H.C., and a Career Development Award (AS-102-CDA-L02) (Academia Sinica) to Y.H.C.