Early expression with the help of NNT using the existing TTG balancer line. Twi-Gal4 of the TTG (Twi-Gal4, 2xEGFP) balancer line is driving the expression of the NNT construct with EGFP deposited maternally (left). Right image shows a time-lapse movie of the TTG balancer line. Time-lapse movies start during cellularization at stage 5 (i.e. 40 min before furrow closure).