The N-ethyl-N-nitrosourea (ENU) ←forward genetic screen is a useful tool for the unbiased discovery of novel mechanisms regulating developmental processes. We recovered the dorothy mutation in such a screen designed to recover recessive mutations affecting craniofacial development in the mouse. Dorothy embryos die prenatally and exhibit many striking phenotypes commonly associated with ciliopathies, including a severe midfacial clefting phenotype. We used exome sequencing to discover a missense mutation in nucleotide binding protein 2 (Nubp2) to be causative. This finding was confirmed by a complementation assay with the dorothy allele and an independent Nubp2 null allele (Nubp2null). We demonstrated that Nubp2 is indispensable for embryogenesis. NUBP2 is implicated in both the cytosolic iron/sulfur cluster assembly pathway and negative regulation of ciliogenesis. Conditional ablation of Nubp2 in the neural crest lineage with Wnt1-cre recapitulates the dorothy craniofacial phenotype. Using this model, we found that the proportion of ciliated cells in the craniofacial mesenchyme was unchanged, and that markers of the SHH, FGF, and BMP signaling pathways are unaltered. Finally, we show evidence that the phenotype results from a marked increase in apoptosis within the craniofacial mesenchyme.
Keywords: Cilia; ENU mutagenesis; Neural crest; Nubp2.
Copyright © 2019 Elsevier Inc. All rights reserved.
Cilia-dependent GLI processing in neural crest cells is required for tongue development.Dev Biol. 2017 Apr 15;424(2):124-137. doi: 10.1016/j.ydbio.2017.02.021. Epub 2017 Mar 9. Dev Biol. 2017. PMID: 28286175 Free PMC article.
Intraflagellar transport 88 (IFT88) is crucial for craniofacial development in mice and is a candidate gene for human cleft lip and palate.Hum Mol Genet. 2017 Mar 1;26(5):860-872. doi: 10.1093/hmg/ddx002. Hum Mol Genet. 2017. PMID: 28069795 Free PMC article.
Cranial neural crest ablation of Jagged1 recapitulates the craniofacial phenotype of Alagille syndrome patients.Hum Mol Genet. 2012 Mar 15;21(6):1374-83. doi: 10.1093/hmg/ddr575. Epub 2011 Dec 8. Hum Mol Genet. 2012. PMID: 22156581 Free PMC article.
ENU mutagenesis as a tool for understanding lung development and disease.Biochem Soc Trans. 2009 Aug;37(Pt 4):838-42. doi: 10.1042/BST0370838. Biochem Soc Trans. 2009. PMID: 19614604 Review.
What's retinoic acid got to do with it? Retinoic acid regulation of the neural crest in craniofacial and ocular development.Genesis. 2019 Jul;57(7-8):e23308. doi: 10.1002/dvg.23308. Epub 2019 Jun 3. Genesis. 2019. PMID: 31157952 Review.