Fig. 2

Expression patterns of zebrafish slit2 mRNA. (A) Expression of slit2 mRNA at the midblastula stage (4 h). (B) Expression of slit2 mRNA at 70% epiboly. Lateral view. (C, D) Expression of slit2 mRNA at 80% epiboly. Expression in the axial mesoderm (am, white arrows) is indicated. C, lateral view; D, dorsal view. (E, F) Expression of slit2 mRNA in 10-h embryos. E, dorsal view; F, lateral view. slit2 mRNA is expressed in the anterior margin of the neural plate (arrowheads), the axial mesoderm (white arrow). (G, H) Expression of slit2 mRNA in 16-h embryos. G, lateral view; H, a close-up view of the somites in a parasagittal section. slit2 mRNA is expressed in the anterior margin of the forebrain (arrowhead), floor plate cells (fp and thin arrow), the hypochord (hc), and the anterior margin of the somites (as). (I) Expression of slit2 mRNA in 18-h embryo. (J–M) Expression of slit2 mRNA in the head region of 48-h embryos. J and K, lateral views; M, dorsal view; L, a sagittal section. In K, the axons in the initial scaffold of the brain are immunohistochemically stained with an antibody for acetylated ;;alpha;-tubulin (brown signals). slit2 mRNA is expressed in the floor plate cells (thin arrows) and their anterior equivalents in the ventral forebrain (thick arrows), and in a small number of cells (asterisks) dorsally adjacent to the supraoptic tract (SOT). tc, tectum; hb, hindbrain; hy, hypothalamus; n, notochord; AC, anterior commissure; DVDT, dorsoventral diencephalic tract; POC, postoptic commissure. Bars, 200 ;;mu;m (A–D, E and F, G and I, J–M), 50 ;;mu;m (H).