title: Zebrafish arl6ip1 is required for neural crest development during embryogenesis.
abstract: BACKGROUND
  Although the embryonic expression pattern of ADP ribosylation factor-like 6 interacting protein 1 (Arl6ip1) has been reported, its function in neural crest development is unclear.
  
  
  RESULTS
  We found that knockdown of Arl6ip1 caused defective embryonic neural crest derivatives that were particularly severe in craniofacial cartilages. Expressions of the ectodermal patterning factors msxb, dlx3b, and pax3 were normal, but the expressions of the neural crest specifier genes foxd3, snai1b, and sox10 were greatly reduced. These findings suggest that arl6ip1 is essential for specification of neural crest derivatives, but not neural crest induction. Furthermore, we revealed that the streams of crestin- and sox10-expressing neural crest cells, which migrate ventrally from neural tube into trunk, were disrupted in arl6ip1 morphants. This migration defect was not only in the trunk neural crest, but also in the enteric tract where the vagal-derived neural crest cells failed to populate the enteric nervous system. We found that this migration defect was induced by dampened Shh signaling, which may have resulted from defective cilia. These data further suggested that arl6ip1 is required for neural crest migration. Finally, by double-staining of TUNEL and crestin, we confirmed that the loss of neural crest cells could not be attributed to apoptosis.
  
  
  CONCLUSIONS
  Therefore, we concluded that arl6ip1 is required for neural crest migration and sublineage specification.
authors.affiliation: Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.
authors.forename: Chi-Tang
authors.initials: CT
authors.lastname: Tu
authors.forename: Tzu-Ching
authors.initials: TC
authors.lastname: Yang
authors.forename: Hsing-Yen
authors.initials: HY
authors.lastname: Huang
authors.forename: Huai-Jen
authors.initials: HJ
authors.lastname: Tsai
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000423:Alcian Blue; D000818:Animals; D002465:Cell Movement / Q000235:genetics / Q000502:physiology*; D019465:Craniofacial Abnormalities / Q000235:genetics; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D055785:Gene Knockdown Techniques; D053823:Hedgehog Proteins / Q000378:metabolism; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009432:Neural Crest / Q000196:embryology* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D053823:Hedgehog Proteins; D009419:Nerve Tissue Proteins; D029961:Zebrafish Proteins; C539178:arl6ip1 protein, zebrafish; C407354:crestin protein, zebrafish; D000423:Alcian Blue