Zebrafish spinal motor neurons studies
To evaluate spinal motor neurons formation in zebrafish, fertilized one-cell hb9-EGFP transgenic lines embryos were injected with control-MO and rapgef1a-MO. At 36-hpf, embryos were dechorionated, anesthetized with 0.016% MS-222 (tricaine methanesulfonate, Sigma-Aldrich, St. Louis, MO). Zebrafish were then oriented on their lateral side (anterior, left; posterior, right; dorsal, top) or dorsal side, and mounted with 3% methylcellulose in a depression slide for observation by fluorescence microscopy. The morphological parameters of spinal motor neurons were quantitatively analyzed (Kanungo et al., 2011; Nakano, Windrem, Zappavigna, & Goldman, 2005; Paquet et al., 2009).