title: Cilia-dependent GLI processing in neural crest cells is required for tongue development.
abstract: Ciliopathies are a class of diseases caused by the loss of a ubiquitous, microtubule-based organelle called a primary cilium. Ciliopathies commonly result in defective development of the craniofacial complex, causing midfacial defects, craniosynostosis, micrognathia and aglossia. Herein, we explored how the conditional loss of primary cilia on neural crest cells (Kif3af/f;Wnt1-Cre) generated aglossia. On a cellular level, our data revealed that aglossia in Kif3af/f;Wnt1-Cre embryos was due to a loss of mesoderm-derived muscle precursors migrating into and surviving in the tongue anlage. To determine the molecular basis for this phenotype, we performed RNA-seq, in situ hybridization, qPCR and Western blot analyses. We found that transduction of the Sonic hedgehog (Shh) pathway, rather than other pathways previously implicated in tongue development, was aberrant in Kif3af/f;Wnt1-Cre embryos. Despite increased production of full-length GLI2 and GLI3 isoforms, previously identified GLI targets important for mandibular and glossal development (Foxf1, Foxf2, Foxd1 and Foxd2) were transcriptionally downregulated in Kif3af/f;Wnt1-Cre embryos. Genetic removal of GLI activator (GLIA) isoforms in neural crest cells recapitulated the aglossia phenotype and downregulated Fox gene expression. Genetic addition of GLIA isoforms in neural crest cells partially rescued the aglossia phenotype and Fox gene expression in Kif3af/f;Wnt1-Cre embryos. Together, our data suggested that glossal development requires primary cilia-dependent GLIA activity in neural crest cells. Furthermore, these data, in conjunction with our previous work, suggested prominence specific roles for GLI isoforms; with development of the frontonasal prominence relying heavily on the repressor isoform and the development of the mandibular prominence/tongue relying heavily on the activator isoform.
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States; Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States.
authors.forename: Grethel
authors.initials: G
authors.lastname: Millington
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States; Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States.
authors.forename: Kelsey H
authors.initials: KH
authors.lastname: Elliott
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States; Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States.
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Chang
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States; Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States.
authors.forename: Ching-Fang
authors.initials: CF
authors.lastname: Chang
authors.affiliation: Department of Dermatology, Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, United States.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Dlugosz
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States; Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States. Electronic address: samantha.brugmann@cchmc.org.
authors.forename: Samantha A
authors.initials: SA
authors.lastname: Brugmann
mesh_terms: D000818:Animals; D017209:Apoptosis; D002465:Cell Movement; D002923:Cilia / Q000378:metabolism*; D017353:Gene Deletion; D053823:Hedgehog Proteins / Q000378:metabolism; D019426:Integrases / Q000378:metabolism; D016547:Kinesins; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism*; D008334:Mandible / Q000196:embryology / Q000378:metabolism; D008648:Mesoderm / Q000473:pathology; D051379:Mice; D008954:Models, Biological; D009132:Muscles / Q000473:pathology; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009432:Neural Crest / Q000378:metabolism* / Q000473:pathology; D038081:Organogenesis; D010641:Phenotype; D015398:Signal Transduction; D013234:Stem Cells / Q000473:pathology; D014059:Tongue / Q000196:embryology* / Q000378:metabolism*; D051155:Wnt1 Protein / Q000378:metabolism; D000075746:Zinc Finger Protein Gli2; D000074290:Zinc Finger Protein Gli3
chemical_list: C000618551:Gli2 protein, mouse; C465571:Gli3 protein, mouse; D053823:Hedgehog Proteins; C490202:Kif3a protein, mouse; D051741:Kruppel-Like Transcription Factors; D009419:Nerve Tissue Proteins; D051155:Wnt1 Protein; D000075746:Zinc Finger Protein Gli2; D000074290:Zinc Finger Protein Gli3; C045073:Cre recombinase; D019426:Integrases; D016547:Kinesins
keywords: Aglossia; Ciliopathies; Craniofacial; Gli; Mouse; Neural crest cell; Primary cilia; Sonic Hedgehog; Tongue development