Fig. S1

Injection of 0.56 ng of foxd3 morpholino per embryo only partially phenocopies the foxd3^zdf10 mutant sympathetic neuron defect. A–D: Side views of 56 hpf wild-type embryos labeled by in situ hybridization expression for tyrosine hydroxylase. foxd3 is required for sympathetic neuron development and loss of foxd3 in foxd3^zdf10 mutants or by knockdown with high doses (20 ng/embryo) of translational blocking morpholino results in the complete loss of th-positive sympathetic neurons. A: Wild-type uninjected control embryo in which there are two clear stripes of th-positive sympathetic neurons in the anterior trunk region (arrowheads). B–D: All embryos shown are from the same treated clutch. Reducing Foxd3 partially (0.56 ng/embryo) decreases the number of th-positive sympathetic neurons, although rare wild-type morpholino treated embryos (D) have an absence of sympathetics (arrowheads). A–D: In contrast to differences in th-positive sympathetic neuron expression, th expression in the hind-brain (arrows) and locus coeruleus (white arrowheads) is similar between control uninjected and wild-type/foxd3 morphants.