Figure 1

Zebrafish mnx family genes are dynamically expressed in PMNs and VeLD interneurons. Lateral views, anterior to the left; all figures are in this orientation unless otherwise noted. MiPs and RoPs are outlined green in panels with islet1 labeling, CaPs and VaPs are outlined blue in panels with islet2a labeling. Segment boundaries are demarcated with diagonal lines. (A-L) RNA expression; two spinal hemisegments are shown in each panel. At 14 hpf, mnx1 is co-expressed with both islet1 (A) and islet2a (B), mnx2a is only co-expressed with islet2a (E, F), and mnx2b is co-expressed with both islet1 (I) and islet2a (J). The VeLD interneuron can be seen expressing both mnx1 (arrowheads A, B) and mnx2b (arrowheads I, J). At 24 hpf, mnx1 maintains co-expression with both islet1 (C) and islet2a (D), mnx2a is co-expressed with both islet1 (G) and islet2a (H), and mnx2b is co-expressed only with islet1 (K, L). VeLD still expresses mnx1 (arrowhead C). (M-N) Protein expression. Mnx2b protein (red) co-localizes with the MiP soma (GFP; green) (M). Mnx1 protein (red) co-localizes with the VeLD soma (GFP; green) (N). (O) Schematic of mnx expression. Scale bar: 10 μm, A-L; 10 μmm M; 20 μm N.