Plug-and-play genetic access to drosophila cell types using exchangeable exon cassettes.
Genetically encoded effectors are important tools for probing cellular function in living animals, but improved methods for directing their expression to specific cell types are required. Here, we introduce a simple, versatile method for achieving cell-type-specific expression of transgenes that leverages the untapped potential of "coding introns" (i.e., introns between coding exons). Our method couples the expression of a transgene to that of a native gene expressed in the cells of interest using intronically inserted "plug-and-play" cassettes (called "Trojan exons") that carry a splice acceptor site followed by the coding sequences of T2A peptide and an effector transgene. We demonstrate the efficacy of this approach in Drosophila using lines containing suitable MiMIC (Minos-mediated integration cassette) transposons and a palette of Trojan exons capable of expressing a range of commonly used transcription factors. We also introduce an exchangeable, MiMIC-like Trojan exon construct that can be targeted to coding introns using the Crispr/Cas system.
Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
Fengqiu
F
Diao
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
Holly
H
Ironfield
Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
Haojiang
H
Luan
Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
Feici
F
Diao
Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
William C
WC
Shropshire
Centro Interdisciplinario de Neurociencia, Universidad de Valparaiso, Pasaje Harrington 287, Playa Ancha, Valparaiso, Chile.
John
J
Ewer
The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, USA.
Elizabeth
E
Marr
The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, USA.
Christopher J
CJ
Potter
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
Matthias
M
Landgraf
Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA. Electronic address: benjaminwhite@mail.nih.gov.
Benjamin H
BH
White
D020121:5' Untranslated Regions; D000818:Animals; D064112:Clustered Regularly Interspaced Short Palindromic Repeats / Q000235:genetics; D004330:Drosophila / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D005091:Exons; D007438:Introns; D022821:RNA Splice Sites; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D019076:Transgenes / Q000235:genetics / Q000502:physiology
D020121:5' Untranslated Regions; D029721:Drosophila Proteins; C557617:GAL4 protein, Drosophila; D022821:RNA Splice Sites; D014157:Transcription Factors