Efficient tissue-type specific expression of target genes in a tetracycline-controlled manner from the ubiquitously active Eef1a1 locus

• Published in: Scientific reports 2020-01, Vol.10 (1), p.207, Article 207
• Main Authors: Sakamoto, Kazuhito, Rädler, Patrick D., Wehde, Barbara L., Triplett, Aleata A., Shrestha, Hridaya, Ferraiuolo, Rosa-Maria, Amari, Foued, Coppola, Vincenzo, Klinakis, Apostolos, Efstratiadis, Argiris, Wagner, Kay-Uwe
• Format: Article
• Language: English
• Subjects: 14/35; 38/5; 42/41; 42/44; 631/1647/1511; 631/1647/334/1874/345; 631/67/70; 64/60; Animals; Anti-Bacterial Agents - pharmacology; Antibiotics; Cancer; Cell activation; Cell differentiation; Cloning; Cre recombinase; Developmental stages; Epithelial cells; Female; Gene Expression Regulation - drug effects; Gene targeting; Genes; Genes, Reporter; Humanities and Social Sciences; Integrases - metabolism; Interferon; Kinases; Ligands; Male; Mammary gland; Medical research; Mice; Mice, Transgenic; multidisciplinary; Mutants; Pancreas; Peptide Elongation Factor 1 - genetics; Peptide Elongation Factor 1 - metabolism; Promoter Regions, Genetic; Proteins; Science; Science (multidisciplinary); Stat5 protein; Survival factor; Tetracycline - pharmacology; Tissue Distribution; Trans-Activators; Transcription activation; Transgenes; Transgenes - physiology; Tumorigenesis
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-57052-z

Using an efficient gene targeting approach, we developed a novel mouse line that expresses the tetracycline-controlled transactivator (tTA) from the constitutively active Eef1a1 locus in a Cre recombinase-inducible manner. The temporally and spatially controlled expression of the EF1-LSL-tTA knockin and activation of tTA-driven responder transgenes was tested using four transgenic lines that express Cre under tissue-specific promoters of the pancreas, mammary gland and other secretory tissues, as well as an interferon-inducible promoter. In all models, the endogenous Eef1a1 promoter facilitated a cell-type-specific activation of target genes at high levels without exogenous enhancer elements. The applicability of the EF1-LSL-tTA strain for biological experiments was tested in two studies related to mammary gland development and tumorigenesis. First, we validated the crucial role of active STAT5 as a survival factor for functionally differentiated epithelial cells by expressing a hyperactive STAT5 mutant in the mammary gland during postlactational remodeling. In a second experiment, we assessed the ability of the EF1-tTA to initiate tumor formation through upregulation of mutant KRAS. The collective results show that the EF1-LSL-tTA knockin line is a versatile genetic tool that can be applied to constitutively express transgenes in specific cell types to examine their biological functions at defined developmental stages.