Figure 4.

FLP-inducible Drosophila DamID system. (A) Principle of the approach. Insertion of a transcriptional terminator (STOP) between the promoter and Dam protein coding sequence blocks the expression of the latter at the level of mRNA synthesis. FRT sites flanking the STOP allow its removal in the presence of FLP recombinase. POI, protein of interest. (B) Dam transgenes with different STOP sequences demonstrate diverse efficiency of Drosophila transgenesis. P.hsp70^min, minimal hsp70 promoter; P.hsp70^FL, full-length hsp70 promoter. All transgenes were integrated at the 51C locus by phiC31 integrase-mediated recombination. For each construct, at least 200 embryos were injected, but no more than 5 independent transformants were collected, meaning that the efficiency of transgenesis could be even higher than 2.5% in some cases. LAM, Lamin Dm0. (C) Methylation in whole adults of STOP-Dam-LAM transgenic flies grown at 18°C. Dam^{4-HT-intein@L127C}-LAM flies were used as a positive control. (D) Quantification of amplified methylated GATC fragments from transgenic flies grown at 18 and 25°C.