GDF3 and Klippel-Feil syndrome 1, autosomal dominant: Zebrafish gdf6a mutants and gdf3 morphants display phenotypes reminiscent of KFS, suggesting that zebrafish are a viable model for studying the role of these ligands in the etiology of KFS and their effect on post-otic neural crest activity (Asai-Coakwell et al., 2007; Asai-Coakwell et al., 2009; Ye et al., 2010).