Bei Marianna
Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA.
J Exp Zool B Mol Dev Evol. 2009 Jul 15;312B(5):437-44. doi: 10.1002/jez.b.21261.
Late tooth morphogenesis is characterized by a series of events that determine crown morphogenesis and the histodifferentiation of epithelial cells into enamel-secreting ameloblasts and of mesenchymal cells into dentin-secreting odontoblasts. Functional ameloblasts are tall, columnar, polarized cells that synthesize and secrete a number of enamel-specific proteins. After depositing the full thickness of enamel matrix, ameloblasts shrink in size and regulate enamel maturation. Amelogenesis imperfecta (AI) is a heterogeneous group of inherited defects in enamel formation. Clinically, AI presents as a spectrum of enamel malformations that are categorized as hypoplastic, hypocalcified, or hypomaturation types, based upon the thickness and hardness of the enamel. The different types of AI are inherited, either as X-linked, autosomal-dominant, or autosomal-recessive traits. Recently, several gene mutations have been identified to cause the subtypes of AI. How these genes, however, coordinate their function to control amelogenesis is not understood. In this review, we discuss the role of genes that play definitive role on the determination of ameloblast cell fate and life cycle based on studies in transgenic animals.
晚期牙齿形态发生的特征是一系列决定牙冠形态发生以及上皮细胞向分泌釉质的成釉细胞和间充质细胞向分泌牙本质的成牙本质细胞组织分化的事件。功能性成釉细胞是高大、柱状、极化的细胞，可合成并分泌多种釉质特异性蛋白质。在沉积完整个厚度的釉质基质后，成釉细胞体积缩小并调节釉质成熟。牙釉质发育不全（AI）是一组遗传性釉质形成缺陷的异质性疾病。临床上，AI表现为一系列釉质畸形，根据釉质的厚度和硬度可分为发育不全型、钙化不全型或成熟不全型。不同类型的AI以X连锁、常染色体显性或常染色体隐性性状遗传。最近，已鉴定出几种基因突变可导致AI的亚型。然而，这些基因如何协调其功能以控制釉质形成尚不清楚。在本综述中，我们基于对转基因动物的研究，讨论了在成釉细胞命运和生命周期的决定中起决定性作用的基因的作用。
