Authors: Ben Ewen-Campen 1; Haojiang Luan 3; Jun Xu 1; Tanuj Thakkar 1; Benjamin White 3; Norbert Perrimon 1,2
Affiliations: 1) Harvard Medical School, Boston, MA; 2) HHMI; 3) National Institute of Mental Health, NIH, Bethesda, MD
Keywords: e. gene targeting and modification; z. other (Genetic tools )
Most of the Gal4 drivers that are commonly used in Drosophila research are not solely expressed in the cells- or tissues-of-interest, but also in additional, often unwanted cells or tissues. To overcome this relative lack of specificity, the split-Gal4 intersectional technique was developed, which has successfully been used to create extraordinarily specific driver lines, including many expressed in only a single cell-type. However, unlike native Gal4, existing split-Gal4 tools cannot be repressed by the Gal80 repressor or any other commonly-used repressor, and therefore cannot be temporally controlled. Here, we present a split-Gal4 system which is fully repressible by Gal80 in vivo. Based on a split-intein, this system drives transgene expression at levels indistinguishable from the original split-Gal4 system, and combines the cell-type specificity of split-Gal4 with the temporal control of native Gal4/Gal80. In addition to creating highly specific genetic driver lines, we show that this system can also be used to systematically map single cell RNAseq clusters to anatomy.