Doctoral Dissertation Research: Cold adaptation and gene expression

博士论文研究：冷适应与基因表达

• 批准号: 2316990
• 负责人: Christopher Schmitt
• 金额: $ 2.72万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2316990&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Cold; adaptation

In the past ~450,000 years, members of the genus Homo migrated multiple times from equatorial Africa to more seasonal and cold climates. Non-shivering thermogenesis – a process by which brown fat generates heat – was likely a key part of the success of our genus in adapting to these environments and helping to facilitate these geographic expansions. The product of the gene UCP1, a protein called thermogenin, drives this process. Nonhuman primates have also expanded from Africa into colder latitudes over the past ~300,000 years. Previously, the investigators found signals of selection in the regulation of this gene in some nonhuman primates. In this doctoral dissertation research project, the investigators validate and expand those findings by using innovative methods and previously collected samples. Students from groups underrepresented in STEM disciplines receive training and professional development through this project.Using an established protocol newly validated for specific species, the investigators chemically convert archived wild nonhuman primate fibroblast cell lines into chemically induced brown adipose (ciBA) cells. Outcomes of the conversion are verified by quantifying RNA expression of UCP1 (which is uniquely expressed in brown adipose) via RT-qPCR, with Oil Red O staining and immunofluorescence staining to observe lipid droplet formation and the completeness of culture conversion. The ciBA are then exposed to norepinephrine to stimulate a cold response in the cell lines, and UCP1 gene expression with and without the cold response are compared using bulk RNA sequencing. Results are used to test the prediction of a derived allele dosage effect in UCP1 expression across four loci, such that each derived allele, previously found to have appeared at higher frequencies in colder climates, will be associated with a significant increase in UCP1 expression. Analyses consider potential covariates like sex, BMI, and body weight. Validation of the investigators previous results suggest that the NST system has undergone positive selection in response to colder climates in nonhuman primates and inform our understanding of this process in our own genus.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.

在过去约 45 万年里，人属成员多次从赤道非洲迁徙到更具季节性和寒冷的气候。非颤抖产热——棕色脂肪产生热量的过程——可能是我们属成功适应这些环境并帮助促进这些地理扩张的关键部分。 UCP1 基因的产物，一种称为产热素的蛋白质，驱动着这一过程。在过去约 30 万年里，非人类灵长类动物也从非洲扩展到了寒冷的纬度地区。此前，研究人员在一些非人类灵长类动物中发现了该基因调控的选择信号。在这个博士论文研究项目中，研究人员通过使用创新方法和之前收集的样本来验证和扩展这些发现。来自 STEM 学科中代表性不足的群体的学生通过该项目接受培训和专业发展。使用针对特定物种新验证的既定方案，研究人员将存档的野生非人灵长类成纤维细胞系化学转化为化学诱导棕色脂肪 (ciBA) 细胞。通过 RT-qPCR 定量 UCP1（在棕色脂肪中独特表达）的 RNA 表达，并使用油红 O 染色和免疫荧光染色来观察脂滴形成和培养物转化的完整性，从而验证转化的结果。然后将 ciBA 暴露于去甲肾上腺素以刺激细胞系中的冷反应，并使用批量 RNA 测序比较有和没有冷反应的 UCP1 基因表达。结果用于测试四个基因座 UCP1 表达中派生等位基因剂量效应的预测，使得先前发现在寒冷气候中以较高频率出现的每个派生等位基因将与 UCP1 表达的显着增加相关。分析考虑了性别、BMI 和体重等潜在协变量。对研究人员之前结果的验证表明，NST 系统已经经历了积极选择，以应对非人类灵长类动物的寒冷气候，并让我们了解我们自己属中的这一过程。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。