Fig. 6. Expression of the zebrafish orthologues of plxna3, plxna4, nrp1a, sema3a and sema3f in the cranial region of zebrafish embryos. (Aa-d) Expression of plxna3, nrp1a, isl1 and plxna4 mRNA in the cranial motoneurons at 36 hpf. Dorsal views; anterior, top. (Ba-h) Expression of sem3a1, sema3a2, sema3f1 and sema3f2 mRNA in the jaw region. Lateral views; anterior, left. Broken lines indicate the posterior margin of BA2. Arrows indicate the expression domains of sema3a1. (C) Schematic of the expression patterns of plxna3, nrp1a (blue) and sema3a1 (red).