Fig. S1

Fig. S1

nrg1 type III is required for Schwann cell migration. (A) Reverse transcriptase PCR (RT-PCR) of 29 hpf embryos injected with buffer (control) or with 6.4 ng nrg1 morpholino (MO). Primers used were to ef1a or to exons flanking the nrg1 MO target, with or without reverse transcriptase. The nrg1 transcript is improperly spliced in 29 hpf embryos injected with 6.4 ng nrg1 morpholino as compared with control-injected embryos (arrowhead). (B) RT-PCR of 30 hpf embryos injected with buffer (control), 12.8 ng or 6.4 ng nrg1 type III morpholino. Primers were designed to ef1a or to regions flanking the splice donor targeted by nrg1 type III morpholino, with or without reverse transcriptase. nrg1 type III transcript is reduced in 30 hpf embryos injected with 6.4 ng nrg1 type III morpholino and absent upon 12.8 ng injection as compared with control-injected embryos (arrowhead). A 3.4 kb PCR product is expected if the intron is retained due to aberrant splicing, which would not be amplified under these PCR conditions. Further studies were performed on embryos injected with 6.4 ng of morpholino. Con, control-injected; H₂O, water control; +RT, with reverse transcriptase; -RT, same samples without reverse transcriptase. Primers to ef1a were used as a control. (C,D) Lateral views of control-injected embryos (C) and embryos injected with 6.4 ng nrg1 type III morpholino (D) at 30 hpf. (E,F) Lateral views of 30 hpf control- and morphant-injected embryos carrying the Foxd3:GFP transgene (green) and stained with anti-acetylated tubulin (acTub, red). Schwann cells have migrated along PLL axons in control (E) but not morphant (F) embryos. Asterisks mark pigment cells, which are also Foxd3:GFP⁺. (C-F) Anterior is to the left and dorsal to the top.