Amelogenin gene (AMEL) encodes for a protein that plays important roles in the organization and structure of enamel. A recent evolutionary analysis of AMELX in mammals has revealed, aside to well-conserved 5' and 3' regions, a variable region located in the largest exon (exon 6), which strongly suggested the possible existence of polymorphism in human AMELX. A detailed analysis of this region was of fundamental importance for genetic studies. We have looked for variations in human AMELX exon 6 from 100 AMELX alleles in a randomized European population, using denaturing high-performance liquid chromatography (dHPLC). We also have looked for AMELX variants in databases, and compared this region in nine primates. There were no variations in the AMELX sequences analysed, but two synonymous single-nucleotide polymorphisms were found in databases. Alignment of the primate exon 6 sequences revealed that AMELX is highly constrained, as illustrated by 100% nucleotide identity found between humans and chimpanzee, and from 99.9 to 94.8% nucleotide identity in the other species. In contrast to what was suspected from the evolutionary analysis, we conclude that AMELX polymorphism should occur at low level in humans. This finding leads us to speculate that the high constraint observed in primate AMELX is related to its location on the X chromosome, and is due to selection at a single locus.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.archoralbio.2007.06.001 | DOI Listing |
Oral Dis
December 2024
Department of Oral Health Sciences-Orthodontics, KU Leuven and Service of Dentistry, University Hospitals Leuven, Leuven, Belgium.
Introduction: To systematically review the available literature reporting on genetic mutations leading to dento-maxillofacial malformations in mice.
Materials And Methods: An electronic search was performed across Embase, PubMed, Web of Science, and Scopus databases up to May 2024, targeting all in vivo studies on gene mutations causing dento-maxillofacial deformities in mice. Studies reporting oral clefts were excluded.
J Prosthet Dent
November 2024
Professor and Chair, Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany; Moorenstraße 5, 40225 Düsseldorf, Germany; and Professor and Chair, Center for Rare Diseases, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Germany; Moorenstraße 5, 40225 Düsseldorf, Germany.
Monogr Oral Sci
September 2024
University Hospital for Conservative Dentistry and Periodontology, Medical University of Innsbruck, Innsbruck, Austria.
Amelogenesis, the intricate process governing enamel formation, is susceptible to a range of genetic, systemic, and environmental influences, resulting in distinct developmental defects of enamel (DDE), such as molar incisor hypomineralisation (MIH), enamel hypoplasia, dental fluorosis, and amelogenesis imperfecta (AI). This chapter aims to provide a comprehensive overview of amelogenesis and DDE, establishing correlations between histopathological findings and clinical manifestations. MIH, a qualitative enamel defect, occurs during the mineralisation and maturation phases, affecting first permanent molars and eventually incisors.
View Article and Find Full Text PDFInt J Mol Sci
June 2024
Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI 48109, USA.
mutations cause X-linked amelogenesis imperfecta (AI), known as AI types IE, IIB, and IIC in Witkop's classification, characterized by hypoplastic (reduced thickness) and/or hypomaturation (reduced hardness) enamel defects. In this study, we conducted whole exome analyses to unravel the disease-causing mutations for six AI families. Splicing assays, immunoblotting, and quantitative RT-PCR were conducted to investigate the molecular and cellular effects of the mutations.
View Article and Find Full Text PDFInt J Mol Sci
April 2024
Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China.
Human-induced pluripotent stem cells (hiPSCs) offer a promising source for generating dental epithelial (DE) cells. Whereas the existing differentiation protocols were time-consuming and relied heavily on growth factors, herein, we developed a three-step protocol to convert hiPSCs into DE cells in 8 days. In the first phase, hiPSCs were differentiated into non-neural ectoderm using SU5402 (an FGF signaling inhibitor).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!