Fig. 1
Tg(8.4neurog1:gfp) is a marker of zebrafish early-born olfactory neurons. (A-F) Single confocal sections of olfactory placodes showing co-expression of HuC/D (A-C) or the previously described pioneer neuron marker zns-2 (D-F) with GFP from the Tg(8.4neurog1:GFP) transgene at 24 hpf. (G-L) Single confocal sections of olfactory placodes showing immunolabelling of HuC/D (G-I) or in situ hybridisation and immunolabelling of omp (J-L) and GFP from the Tg(8.4neurog1:GFP) transgene at 48 hpf. Whereas all GFP-positive cells in the placode are HuC/D- and zns-2-positive at 24 hpf, at 48 hpf HuC/D+/GFP–cells are present; little, if any, overlap is detected between the expression of omp transcripts and GFP at 48 hpf. (M,N) Schematics of olfactory placodes at 24 hpf (M) or 48 hpf (N). Early-born olfactory neurons are shown in green and olfactory sensory neurons in red. A, anterior; L, lateral; M, medial; P, posterior; T, telencephalon. Scale bars: 10 μm.