Nucleic Acids Res. 2015 Apr 30;43(8):e56. doi: 10.1093/nar/gkv113. Epub 2015 Feb 20.

Gene-specific cell labeling using MiMIC transposons.

Author information

1: Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
2: Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA Department of Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA Dan L. Ducan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA Program in Integrative and Molecular Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA Dierick@bcm.edu.
3: Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA Dierick@bcm.edu.

Abstract

Binary expression systems such as GAL4/UAS, LexA/LexAop and QF/QUAS have greatly enhanced the power of Drosophila as a model organism by allowing spatio-temporal manipulation of gene function as well as cell and neural circuit function. Tissue-specific expression of these heterologous transcription factors relies on random transposon integration near enhancers or promoters that drive the binary transcription factor embedded in the transposon. Alternatively, gene-specific promoter elements are directly fused to the binary factor within the transposon followed by random or site-specific integration. However, such insertions do not consistently recapitulate endogenous expression. We used Minos-Mediated Integration Cassette (MiMIC) transposons to convert host loci into reliable gene-specific binary effectors. MiMIC transposons allow recombinase-mediated cassette exchange to modify the transposon content. We developed novel exchange cassettes to convert coding intronic MiMIC insertions into gene-specific binary factor protein-traps. In addition, we expanded the set of binary factor exchange cassettes available for non-coding intronic MiMIC insertions. We show that binary factor conversions of different insertions in the same locus have indistinguishable expression patterns, suggesting that they reliably reflect endogenous gene expression. We show the efficacy and broad applicability of these new tools by dissecting the cellular expression patterns of the Drosophila serotonin receptor gene family.