Tcof1/Treacle Is Required for Neural Crest Cell Formation and Proliferation Deficiencies That Cause Craniofacial Abnormalities

• Published in: Proceedings of the National Academy of Sciences - PNAS 2006-09, Vol.103 (36), p.13403-13408
• Main Authors: Dixon, Jill, Jones, Natalie C., Sandell, Lisa L., Jayasinghe, Sachintha M., Crane, Jennifer, Rey, Jean-Philippe, Dixon, Michael J., Trainor, Paul A.
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Apoptosis - genetics; Biological Sciences; Cell cycle; Cell growth; Cell Proliferation; Craniofacial Abnormalities - embryology; Craniofacial Abnormalities - genetics; Craniofacial Abnormalities - pathology; Crosses, Genetic; Embryo Culture Techniques; Embryonic stem cells; Embryos; Genes; Genetics; Heterozygote; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Mice; Mice, Congenic; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Mutant Strains; Molasses; Neural crest; Neural Crest - cytology; Neural Crest - embryology; Neural Crest - physiology; Neural stem cells; Neurons; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Phosphoproteins - genetics; Phosphoproteins - metabolism; Ribosomes; RNA, Ribosomal - analysis; RNA, Ribosomal - metabolism; Rodents; Stem cells
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0603730103

Neural crest cells are a migratory cell population that give rise to the majority of the cartilage, bone, connective tissue, and sensory ganglia in the head. Abnormalities in the formation, proliferation, migration, and differentiation phases of the neural crest cell life cycle can lead to craniofacial malformations, which constitute one-third of all congenital birth defects. Treacher Collins syndrome (TCS) is characterized by hypoplasia of the facial bones, cleft palate, and middle and external ear defects. Although TCS results from autosomal dominant mutations of the gene TCOF1, the mechanistic origins of the abnormalities observed in this condition are unknown, and the function of Treacle, the protein encoded by TCOF1, remains poorly understood. To investigate the developmental basis of TCS we generated a mouse model through germ-line mutation of Tcof1. Haploinsufficiency of Tcof1 leads to a deficiency in migrating neural crest cells, which results in severe craniofacial malformations. We demonstrate that Tcof1/Treacle is required cell-autonomously for the formation and proliferation of neural crest cells. Tcof1/Treacle regulates proliferation by controlling the production of mature ribosomes. Therefore, Tcof1/Treacle is a unique spatiotemporal regulator of ribosome biogenesis, a deficiency that disrupts neural crest cell formation and proliferation, causing the hypoplasia characteristic of TCS craniofacial anomalies.