Fig. 1. Molecular markers uniquely identify all NB7-3 progeny neurons. (A) Schematic representation of the NB7-3 lineage showing molecular markers of the four neuronal progeny, axonal projections and positions relative to the midline (M), anterior commissure (A) and posterior commissure (P). Ddc and corazonin are cytoplasmic antigens; all others are nuclear. The yellow numbers 1, 2 and 3 label the EW1, EW2 and EW3 neurons, respectively. M indicates the midline. (B,C) One abdominal segment from the ventral cord of stage 15 eg²⁸⁹/+ embryos, shows the four Eg-lacZ positive neurons of the NB7-3 lineage. The EW2 and EW3 neurons express Zfh-2 (orange cells). (B) The GW and EW1 neurons express Hb (purple cells). (C) The GW neuron expresses Zfh-1 (purple cell). (D-F) One abdominal segment from the ventral cord of stage 17 eg²⁸⁹/+ embryos. (D) The two serotonergic neurons (1, 2) express Ddc and can be distinguished by their differential expression of Hb and Zfh-2. (E) The EW3 neuron expresses corazonin. (F) The EW2 neuron expresses Pdm1. The GW neuron is usually not detectable at stage 17. Scale bars: in C, 5 µm for B,C; in F, 5 µm for D-F.