DNA methyltransferase 3B regulates duration of neural crest production via repression of Sox10

• Published in: Proceedings of the National Academy of Sciences - PNAS 2014-12, Vol.111 (50), p.17911-17916
• Main Authors: Hu, Na, Strobl-Mazzulla, Pablo H., Simoes-Costa, Marcos, Sánchez-Vásquez, Estefania, Bronner, Marianne E.
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Biological Sciences; Cell lines; Chick Embryo; Chromatin Immunoprecipitation; Deoxyribonucleic acid; DNA; DNA (Cytosine-5-)-Methyltransferases - genetics; DNA (Cytosine-5-)-Methyltransferases - metabolism; DNA Methylation - physiology; DNA Methyltransferase 3B; Electroporation; Embryos; Emigration; Enzymes; Epithelial-Mesenchymal Transition - genetics; Epithelial-Mesenchymal Transition - physiology; Gene Expression Regulation, Developmental - genetics; Gene Expression Regulation, Developmental - physiology; Genes; Immunohistochemistry; In Situ Hybridization; Methylation; Molecular Sequence Data; Multipotent stem cells; Nervous system; Neural crest; Neural Crest - cytology; Neural Crest - embryology; Neural stem cells; Neurons; Promoter regions; Promoter Regions, Genetic - genetics; Sequence Analysis, DNA; SOXE Transcription Factors - metabolism; Stem cells
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1318408111

Neural crest stem cells arise within the central nervous system but then undergo an epithelial-to-mesenchymal transition to migrate away and contribute to the peripheral nervous system and craniofacial skeleton. Here we show that DNA methyltransferase 3B (DNMT3B) is responsible for the loss of competence of dorsal neural tube cells to generate emigrating neural crest cells. DNMT3B knockdown results in up-regulation of neural crest markers, prolonged neural crest emigration, and subsequent precocious neuronal differentiation of the trigeminal ganglion. We find that DNMT3B binds to the promoter of Sox10 , known to be important for neural crest emigration and lineage acquisition. Bisulfite sequencing further reveals methylation of the Sox10 promoter region upon cessation of emigration in normal embryos, whereas this mark is reduced after DNMT3B loss. Taken together, these results reveal the importance of DNA methylation in regulating the ability of neural tube cells to produce neural crest cells and the timing of peripheral neuron differentiation. Significance Mutations of DNA methyltransferase 3B (DNMT3B) result in facial abnormalities and neurologic defects in humans related to abnormal neural crest development. To address the underlying mechanism, we tested the role of DNMT3B using loss- of-function and molecular analyses in chick embryos. Neural crest cells initially form within the central nervous system (CNS), then migrate away to form elements of the facial skeleton and peripheral nervous system (PNS). Our results show that DNMT3B acts by directly methylating the promoter region of the neural crest gene Sox10 in neural tube progenitors, thereby inhibiting its transcription. This in turn influences the duration of neural crest production by the CNS, such that DNMT3B loss causes overproduction of neural crest cells and premature neuronal differentiation in the PNS.