Fig. 7. nrg2a alone is unnecessary for DRG neuron formation. DRG neurons labeled with Elavl antibody at 4 dpf. DRG neurons in controls (A,C). DRG neurons are missing from some segments of nrg2a MO-injected embryos (B) but appear normal in nrg2b MO-injected embryos (D). Asterisks indicate absent DRG neurons in B. (E) RT-PCR showing that nrg2a MOs cause incorrect mRNA splicing through 3 dpf, but by 4 dpf, both incorrectly-spliced and correctly-spliced transcripts are present. (F) RT-PCR showing that both the nrg2a and nrg2b MOs cause incorrect splicing at 25 hpf. Scale bar: 20 µm.