The Evolution of Cranial Neural Crest in Mammals: The Genetic Origins of Heterochronic Change

哺乳动物颅神经嵴的进化：异时性变化的遗传起源

• 批准号: 0316353
• 负责人: Kathleen Smith
• 金额: $ 33.03万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0316353&HistoricalAwards=false
• 关键词: Evolution; Cranial; Neural; Crest; Mammals

0316353SmithMarsupial and placental mammals are distinguished by their reproductive and life history strategies. All marsupials are highly altricial at birth, but must possess sufficient functional independence to function at this altricial state. Previous work has shown that when compared to other mammals, the cranial neural crest differentiates early relative to the neural or mesodermal tissues in marsupials. This is of interest as proper craniofacial patterning depends on a series of intricate relations between these tissues. The current proposal will examine the relation between genetic differentiation of the neural plate differentiation and neural crest differentiation and migration. Specific aims: The specific aims of the current proposal are: 1) To test hypotheses that subpopulations of first arch crest, must be segregated in order to establish proper muscular-skeletal patterning in the first arch. 2) To examine the possible role of the isthmus as an organizing center in at the midbrain/hindbrain boundary, by establishing the relation between FGF8 expression, and Hoxa2 expression in the neural plate and migrating neural crest cells into aches 1 and 2. 3) To test the hypothesis that genetic differentiation of R3 and R5 as exhibited by Krox 20 expression is a necessary component of the suppression of neural crest migration from these zones. Intellectual merit: This study will contribute to the understanding of a number of specific mechanisms of craniofacial patterning in vertebrates and in particular the role of neural crest in that patterning. Further, this project is part of a long-term study of the ways that developmental changes produce evolutionary changes. Finally, the study speaks to the constraints and possibilities of change in development, and helps reveal the ways in which developmental mechanisms may evolve.Broader impacts: The most important is educational. The previous grant supported the work of 14 undergraduates. Two were supported on REU supplements, including a woman of African American descent and a woman of Latin-American descent. Thirteen of these students were women. Educating undergraduates (and in particular under-represented groups) by providing research experience has been a life long pattern, and support by NSF will allow the Smith lab to continue to contribute to science education. In addition, during the past 10- years of NSF funding one of the larger collections of marsupial embryos in the world has accumulated. In the past two years this collection has been used by individuals from Finland, Germany, Brazil and the US. Further funding will support this collection. .

有袋动物和胎盘哺乳动物的区别在于它们的繁殖和生活史策略。所有有袋动物在出生时都是高度晚育的，但必须具有足够的功能独立性才能在这种晚育状态下发挥作用。先前的研究表明，与其他哺乳动物相比，有袋动物的颅神经嵴分化早于神经或中胚层组织。这是有趣的，因为正确的颅面模式依赖于这些组织之间一系列复杂的关系。本研究将探讨神经板分化与神经嵴分化的遗传分化与迁移的关系。具体目标：当前提案的具体目标是：1)为了在第一拱中建立适当的肌肉-骨骼模式，必须将第一拱嵴的亚种群分开，以检验假设。2)通过建立神经板中FGF8表达与Hoxa2表达以及神经嵴细胞迁移至aches 1和aches 2之间的关系，探讨峡部作为中脑/后脑边界组织中心的可能作用。3)验证由krox20表达所表现的R3和R5的遗传分化是抑制神经嵴从这些区域迁移的必要组成部分的假设。智力价值：这项研究将有助于理解脊椎动物颅面模式的一些特定机制，特别是神经嵴在该模式中的作用。此外，这个项目是对发育变化产生进化变化的长期研究的一部分。最后，该研究说明了发展变化的限制和可能性，并有助于揭示发展机制可能演变的方式。更广泛的影响：最重要的是教育。先前的拨款资助了14名本科生的工作。有两名妇女获得了资源补充支助，包括一名非裔美国妇女和一名拉丁美洲妇女。这些学生中有13名是女性。通过提供研究经验来教育本科生（尤其是代表性不足的群体）是一种终身模式，NSF的支持将使史密斯实验室继续为科学教育做出贡献。此外，在过去的10年里，在美国国家科学基金会的资助下，世界上最大的有袋动物胚胎收藏之一已经积累起来。在过去的两年里，这个系列已经被来自芬兰、德国、巴西和美国的个人使用。进一步的资金将支持这个收藏。