Doctoral Dissertation Research: Characterization and Functional Validation of the Genetic Architecture of Skin Pigmentation

博士论文研究：皮肤色素沉着遗传结构的表征和功能验证

• 批准号: 2142101
• 负责人: Brenna Henn
• 金额: $ 3.02万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-15 至 2024-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2142101&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Characterization; Functional

Research on the evolution of human skin pigmentation includes the characterization of this characteristic's underlying genetic variation. Recent studies have shown that the number of genes associated with skin pigmentation differs across populations and that much of this genetic variation is still unidentified due to underrepresentation of some populations in human genetic research. This doctoral dissertation project lays the groundwork necessary to model human skin pigmentation evolution by characterizing and functionally validating the genetic architecture of skin pigmentation in a population that has been underrepresented in such research. Data generated from this project can inform several pigmentation research objectives, including understanding the role of natural selection in shaping this human trait. The project can also be used as a model for research on other complex genetic traits and may inform other fields including bioarchaeology and forensic anthropology. Additionally, this project contributes to the skill development of undergraduate and graduate students through wet lab, computational, and fieldwork training.The research team conducts fieldwork to collect paired genetic and pigmentation data from individuals in a population with high levels of ancestral alleles and higher levels of genetic diversity than other extant human populations. The research presents an opportunity to research pigmentation variation that may have been present in ancestral human populations, and therefore potentially broadens our understanding of pigmentation genetics globally. Newly collected samples will be genotyped and then evaluated using a genome-wide association (GWA) approach. Data from four different descent populations will be meta-analyzed to increase power to detect low-effect size loci. Regions identified in the GWA study are not necessarily causal pigmentation loci, rendering functional validation necessary. Top candidate genes are therefore identified and functionally evaluated for causality with CRISPR (clustered regularly interspaced short palindromic repeats) gene editing in zebrafish, an effective model organism to study human skin pigmentation. Using a rapid automated phenotyping platform to image larvae, pigmentation is analyzed comparing CRISPR- mosaic “knockout” fish with “mock” injected sibling controls. This strategy can functionally verify whether novel associated genes from the GWAS are causal pigmentation genes.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.

对人类皮肤色素沉着进化的研究包括对这一特征的潜在遗传变异的表征。最近的研究表明，与皮肤色素沉着相关的基因数量在不同人群中存在差异，而且由于某些人群在人类遗传研究中的代表性不足，这种遗传变异的大部分仍然无法确定。这个博士论文项目奠定了必要的基础，通过表征和功能验证皮肤色素沉着的遗传结构，在这样的研究中一直代表性不足的人口模型人类皮肤色素沉着的演变。该项目产生的数据可以为几个色素沉着研究目标提供信息，包括了解自然选择在塑造这种人类特征中的作用。该项目还可以作为研究其他复杂遗传特征的模型，并可能为生物考古学和法医人类学等其他领域提供信息。此外，该项目通过湿实验室、计算和实地考察培训，为本科生和研究生的技能发展做出了贡献。研究团队进行实地考察，从具有高水平祖先等位基因和遗传多样性水平高于其他现存人群的人群中收集配对的遗传和色素沉着数据。这项研究提供了一个研究可能存在于祖先人群中的色素变化的机会，因此有可能扩大我们对全球色素遗传学的理解。将对新采集的样本进行基因分型，然后使用全基因组关联（GWA）方法进行评价。将对来自四个不同血统人群的数据进行荟萃分析，以提高检测低效应大小基因座的能力。在GWA研究中确定的区域不一定是因果色素沉着位点，因此需要进行功能验证。因此，在斑马鱼中识别出了最佳候选基因，并在功能上评估了与CRISPR（成簇的规则间隔短回文重复序列）基因编辑的因果关系，斑马鱼是研究人类皮肤色素沉着的有效模式生物。使用快速自动化表型分析平台对幼虫进行成像，比较CRISPR-嵌合“敲除”鱼与“模拟”注射的同胞对照，分析色素沉着。该策略可以在功能上验证来自GWAS的新相关基因是否是致病色素沉着基因。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。