Fig. 1

Fig. 1

Motoneuron and beta-cell specific GFP expression in Tg[hb9:GFP]^ml2 embryos. (A) Schematic representation of the hb9 gene from different species. Highlighted are conserved non-coding regions (dark green), and exons (coding sequences in grey, untranslated regions in blue). (B–I2) In situ hybridization analysis comparing mRNA expression of hb9 (B, D, D2) and gfp (C, E, E2) in Tg[hb9:GFP]^ml2 embryos at 17 hpf (B, C) and 24 hpf (D, E) reveals similar pattern in motoneurons and ventral interneurons (B–E, white arrows) and pancreas (B, C, white arrowheads). Asterisk in C marks ectopic gfp expression in rhombomere. D2, E2 show different focal planes of the embryos shown in D, E. (F–I) Confocal image projections of Tg[hb9:GFP]^ml2 embryos labelled with GFP (green) and islet antibodies (red) at 16 hpf (F), 19 hpf (G) and 24 hpf (H) show overlapping expression of GFP and islet proteins in motoneurons (arrows) and in a subset of endocrine cells (arrowheads). (H–I2) Confocal image stacks of Tg[hb9:GFP]^ml2 embryos labelled with antibodies for GFP and pancreatic hormones at 24 hpf (H2) and 48 hpf (I, I2) show that GFP overlaps with insulin (blue in H2, I) but not with glucagon (Glu) and somatostatin (Sst) (Glu + Sst in red, I2). Embryos are shown in dorsal (B–E) or ventral (F–I) view with anterior to the left. Scale bars in all figures correspond to 50 μm.