<i>fscn1a</i> is required for filopodia formation in NC cells.

<p>(A) Dorsal cranial views of cranial NC streams in 26 hpf <i>Tg(sox10:rfpmb)</i> and <i>Tg(sox10:rfpmb); fscn1a MZ</i> embryos, anterior is to the left. Numbers correspond to pharyngeal arches, e = eye, ov = otic vesicle, nt = neural tube, scale bar = 100μm. Leading edge of NC stream 1 is enlarged in right panel, scale bar = 10 μm. Arrows highlight filopodia at leading edge of NC stream 1. (B-C) Time lapse confocal images of filopodia at the leading edge of NC stream 2 (B) or of leading cells in trunk NC streams (C) in live <i>Tg(sox10:rfpmb)</i> and <i>Tg(sox10:rfpmb)</i>; <i>fscn1a MZ</i> embryos at 26 hpf. Arrows highlight tips of single filopodia throughout the time lapses. Scale bar = 10 μm. (D) Quantitation of filopodia number, mean and maximum filopodia length, and change in filopodia length in <i>Tg(sox10:rfpmb)</i> and <i>Tg(sox10:rfpmb); fscn1a MZ</i> cranial NC (n = 6 embryos and 30 filopodia each for <i>Tg(sox10:rfpmb)</i> and <i>Tg(sox10:rfpmb); fscn1a MZ</i>, ****p<0.0001).