NSF Postdoctoral Fellowship in Biology FY 2021: Uncovering the Mechanisms of Convergent Tooth Loss in Frogs

该行动资助了2021财年的NSF生物学博士后研究奖学金，即调查基因组，环境和表型之间相互作用的生命规则的综合研究。该研究金支持研究员的研究和培训，以创新的方式为生活规则领域做出贡献。牙齿存在于大多数现存的脊椎动物中。然而，在一些鱼类、爬行动物和哺乳动物中，牙齿完全脱落。虽然两栖动物牙齿的排列和状况研究得很少，但最近的研究表明，青蛙的牙齿已经脱落了20多次。青蛙牙齿脱落的潜在机制尚不清楚，但研究可能的发育，遗传和环境因素将从进化的角度深入了解这一过程的可预测性和可重复性。该项目的目的是确定是否存在牙齿发育所需的核心基因组，并测试环境（温度）是否会影响牙齿发育。该奖学金将通过为本科生提供研究机会来促进导师培训。将为中学教师和学生创建数字解剖资源，利用博物馆标本提供通过自然选择进化的真实的例子。鱼类和蝾螈牙齿的增殖至少由四种主要的信号通路介导，不同信号的丢失会阻止牙齿的发育，并成为鸟类、海龟和一些哺乳动物牙齿脱落的基础。由于在遗传学上广泛的牙齿缺失和上颌骨和下颌的单独进化损失，青蛙为研究重复特征丧失的机制提供了无与伦比的机会。该研究员将使用免疫组织化学，原位杂交和转录组学来表征两栖动物的牙齿发育，并评估不同的信号是否会阻止独立失去牙齿的物种的牙齿发育。在四足动物中，牙釉质和牙本质只存在于牙齿中，这些组织是由牙齿特异性、非多效性基因编码的蛋白质形成的。比较基因组学将用于确定牙釉质和牙本质基因是否通过新的失活突变在无牙青蛙中变得无功能。环境因素可能通过改变发育速率来影响牙齿解剖结构。实验方法将被用来测试，如果一个这样的因素，温度，影响青蛙牙列的解剖和表达模式。创建解剖学教育数字资源和PI参与指导本科生和推广将扩大该项目的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Teeth are present in most living vertebrates. However, complete tooth loss has evolved in a few groups of fishes, reptiles, and mammals. Though the arrangement and condition of amphibian teeth has been poorly studied, recent work shows that frogs have lost teeth more than 20 times. The mechanisms underlying tooth loss in frogs are unknown, but examining possible developmental, genetic, and environmental factors will provide insight to how predictable and repeatable this process is from an evolutionary point of view. The aim of this project is to determine if there is a core set of genes required for tooth development, and to test if the environment (temperature) can affect tooth development. The fellowship will facilitate mentorship training by fostering research opportunities for undergraduate students. Digital anatomy resources will be created for middle school teachers and students to provide real examples of evolution through natural selection using museum specimens. The proliferation of teeth in fishes and amniotes is mediated by at least four major signaling pathways, and the loss of different signals arrests dental development and underlies tooth loss in birds, turtles, and some mammals. With phylogenetically widespread tooth loss and separate evolutionary losses on upper and lower jaws, frogs offer an unparalleled opportunity for investigating the mechanisms of repeated trait loss. The fellow will use immunohistochemistry, in situ hybridization, and transcriptomics to characterize dental development in amphibians and assess if different signals arrest tooth development among species that have independently lost teeth. Within tetrapods, enamel and dentin are found only in teeth, and these tissues are formed by proteins encoded by tooth-specific, non-pleiotropic genes. Comparative genomics will be used to identify if enamel and dentin genes have become non-functional in toothless frogs via novel inactivating mutations. Environmental factors may impact dental anatomy by altering developmental rate. An experimental approach will be used to test if one such factor, temperature, impacts the anatomy and expression patterns of frog dentition. Creation of digital resources for anatomy education and PI participation in mentoring undergraduate students and outreach will broaden the impact of the project.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.