• Drosophila ;
  • genome editing;
  • TAL effector nuclease

We report here a case study of TALEN-induced gene knock out of the trachealess gene of Drosophila. Two pairs of TALEN constructs caused targeted mutation in the germ line of 39% and 17% of injected animals, respectively. In the extreme case 100% of the progeny of TALEN-injected fly was mutated, suggesting that highly efficient biallelic germ line mutagenesis was achieved. The mutagenic efficiency of the TALEN pairs paralleled their activity of single strand annealing (SSA) assay in cultured cells. All mutations were deletion of 1 to 20 base pairs. Merit and demerit of TALEN-based gene knockout approach compared to other genome editing technologies is discussed.