Evolutionary Genetic Approaches to Dental Anthropology

人类和其他灵长类动物有复杂的牙齿，由不同数量、类型、形状和大小的牙齿组成。在生物发育的基本性质中，一个重要的问题是了解这些结构是如何产生的遗传基础。从伦理上讲，我们不能直接对灵长类动物进行研究，因为关键的发育事件发生在胚胎中。然而，这个问题可以在实验室小鼠中进行研究。我们和其他人已经确定了在小鼠牙齿发育过程中表达的基因，并将使用各种实验方法使这些基因失活，以确定它们在这一过程中的作用。此外，我们将采用现代DNA测序方法（称为EST鉴定），寻找在门牙或磨牙发育过程中表达的基因，但不是两者都表达，因此可能有助于确定牙齿的类型。这些基因在牙胚发育过程中的表达将被描述。因为老鼠的牙齿不完整，我们不能把在它们身上的发现自动地应用到人类或相关的灵长类动物身上。然而，我们将在实验室负鼠身上观察相同基因的表达，负鼠确实有完整的牙齿，类似于人类和其他灵长类动物，以确定牙齿模式中的恒定元素，然后我们可能会以各种方式在人类身上进行研究（不属于这个项目的一部分）。总的来说，我们期望这项工作将导致对牙列或其他类似复杂特征如何在胚胎中产生以及它们如何在物种之间变化的理解。

Humans and other primates have complex dentitions, consisting of teeth of various numbers, types, shapes, and sizes. An important problem in the basic nature of biological development, is to understand the genetic basis for how such structures are produced. We cannot ethically work directly on primates because the critical developmental events take place in the embryo. However, this problem can be studied in the laboratory mouse. We and others have identified genes that are expressed in developing mouse teeth, and will use various experimental methods to inactivate these genes to determine their role in the process. In addition, we will be taking a modern DNA sequencing approach (called EST identification), to find genes that are expressed in developing incisors or molars, but not both, and hence may help determine the type of tooth. The expression of these genes in developing tooth germs will be characterized. Because mice have incomplete dentitions we cannot translate findings in them automatically to humans or related primates. However, we will be looking at the expression of the same genes in the laboratory possum, which does have a complete dentition, similar to humans and other primates, to identify constant elements in dental patterning which we might then study in humans in various ways (not part of this project). Generally, we expect this work will lead to an understanding of how the dentition, or other similarly complex traits, are produced in an embryo and how they vary among species.