Craniofacial Development in Eutherian and Metatherian Mammals

真兽类和后兽类哺乳动物的颅面发育

• 批准号: 9007480
• 负责人: Kathleen Smith
• 金额: $ 7.3万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-10-15 至 1992-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9007480&HistoricalAwards=false
• 关键词: Craniofacial; Development; Eutherian; Metatherian; Mammals

The most significant differences between eutherian (placental) and metatherian (marsupial) mammals involve their modes of reproduction and development. Metatherians are born at a premature state relative to eutherians, and complete development while attached to the teat, nursing. The evolutionary consequences, advantages and disadvantages of these metatherian and eutherian strategies form the basis of an extensive literature. Yet, most details on the differences in morphological development are unknown. The proposed study will examine development of craniofacial features in metatherians and eutherians and is intended to form the first part of a long term study of craniofacial development in mammals. The focus of this specific project is on a detailed comparison of craniofacial development in two species, Monodelphis domestica (Didelphidae, Marsupialia), and Meoscricetus auratus (Rodentia). These are hypothesized as representative taxa for the two groups. Data on rate of development, on sequence of differentiation, and on coordination of developmental events will be collected for both species. Focus will be on the bones, muscles and nerves of the head. These data will then be applied in a preliminary manner in phylogenetic comparisons in order to assess the generality of patterns observed in these representative taxa and to form hypotheses on appropriate characters for further examination of the polarity of developmental events in placental and marsupial mammals.

真兽类（胎盘类）和后兽类（有袋类）哺乳动物之间最显著的差异包括它们的繁殖和发育模式。相对于真兽，后生兽出生在一个过早的状态，并在依附于乳头，哺乳时完成发育。进化的结果，优势和劣势，这些后therian和eutherian策略形成了广泛的文献基础。然而，关于形态发育差异的大多数细节是未知的。这项拟议的研究将检查后生动物和真生动物颅面特征的发育，并打算形成哺乳动物颅面发育长期研究的第一部分。本项目的重点是详细比较两种动物的颅面发育，即家蝇（有袋目）和金齿目（啮齿目）。这些被假设为两个群体的代表性分类群。将收集这两个物种的发育速度、分化顺序和发育事件协调方面的数据。重点将放在头部的骨骼、肌肉和神经上。然后，这些数据将以初步的方式应用于系统发育比较，以评估在这些代表性分类群中观察到的模式的普遍性，并形成关于适当特征的假设，以进一步研究胎盘和有袋哺乳动物发育事件的极性。