Improved methods for inference of genotype-specific response to environmental toxins

项目摘要 为什么有些人似乎比其他人对环境干扰更敏感？的答案 这个问题具有广泛的影响，从我们预测疾病风险的能力， 基因型，我们识别个体间变异驱动因素的能力。在这里，我们建议研究广泛的 遗传和环境变异之间的相互作用如何介导疾病风险 在有毒环境暴露后死亡具体来说，我们将研究 六价铬[Cr（VI）]是一种普遍存在的环境污染物。Cr（VI）为 一种强致癌物，其毒性远远超出其遗传毒性效应，包括神经毒性， 线粒体缺陷、免疫畸变和生殖缺陷，仅举几例。虽然Cr（VI）是常见的 环境和主要健康危害，我们对遗传变异如何驱动差异化 其毒性的易感性，或涉及的分子途径。探索基因型的贡献- 环境与个体差异的相互作用对人类来说是非常具有挑战性的。为了解决这个问题 我们创建了一个新的社区资源来研究果蝇复杂性状变异的遗传基础 由大的、合成的远系繁殖的种群组成的黑腹动物。有了这个新的和多功能的社区资源，我们 可以从一个共同的基因库中培育出数千只基因独特的苍蝇，将它们暴露在一系列 不同的环境[这里，Cr（VI）]，并对比随后的遗传结构。我们同时 开发了一种新的高通量方案来测序DNA和分析数千个转录组， 以非常低的成本飞行，允许先进的系统遗传学分析。利用这个平台，在目标1中，我们将 表型数以千计的个体苍蝇的各种性状已知受到Cr（VI）暴露的影响。这 设计改进和技术进步相结合， 和基因分辨率。它使我们能够问，一些人在环境中经历的敏感性的转变是否 环境胁迫可以解释为通过GxE释放遗传易感性。在目标2中，我们将 运用系统遗传学方法从调节系统的角度研究敏感性的变化 破坏对环境压力更敏感的个体， 对许多基因的鲁棒性。这种鲁棒性的变化似乎受到遗传控制，我们有 开发了一个分析框架，以确定这种依赖于上下文的转录网络及其遗传 监管部门最后，在目标3中，我们研究了环境敏感的等位基因是如何依赖于背景的， 是什么遗传因素调节了他们的智力？我们将使用CRISPR/Cas9敲除和敲入等位基因， 并将这些转基因品系与来自aim 1的合成果蝇杂交 并对F1子代进行Cr（VI）反应的基因分型和表型以鉴定修饰剂。

PROJECT SUMMARY Why do some individuals appear to be more sensitive than others to environmental perturbation? The answer to this question has broad implications ranging from our ability to make predictions about disease risk from genotype, to our ability to identify the drivers of inter-individual variability. Here, we propose to study the broad question of how the interplay between genetic and environmental variation mediates disease risk following a toxic environmental exposure. Specifically, we will examine the consequences of environmental exposure to hexavalent chromium [Cr(VI)] a ubiquitous environmental pollutant. Cr(VI) is a potent carcinogen and its toxicity extends far beyond its genotoxic effects, including neurotoxicity, mitochondrial defects, immune aberrations, and reproductive defects, to list a few. Although Cr(VI) is a common environmental and major health hazard, we know little about how genetic variation drives differential susceptibility to its toxicity, or the molecular pathways involved. Exploring the contribution of genotype-by- environment interactions to individual variation has been very challenging in humans. To address this problem we created a new community resource to study the genetic basis of complex trait variation in Drosophila melanogaster made of large, synthetic outbred populations. With this new and versatile community resource, we can rear thousands of genetically unique flies drawn from a common genetic pool, expose them to a range of different environments [here, Cr(VI)], and contrast the ensuing genetic architectures. We have simultaneously developed a new high throughput protocols to sequence the DNA and assay the transcriptome of thousands of flies at very low cost allowing for advance systems genetics analysis. Using this platform, in aim 1, we will phenotype thousands of individual flies for a variety of traits know to be impacted by Cr(VI) exposure. This combination of design improvements and technological advances produces a large boost in both statistical power and genetic resolution. It allows us to ask if the shift in sensitivity some individuals experience under environmental stress can be explained by the release of genetic susceptibility through of GxE. In aims 2, we will use a systems genetic approach study variation in sensitivity from the perspective of the regulatory systems disruption. Individuals more sensitive to environmental stress appear to have decreased transcriptional robustness for many genes. This variation in robustness appears to be under genetic control and we have developed an analytical framework to identify such context-dependent transcriptional networks and their genetic regulators. Finally, in aim 3, we examine how environmentally sensitive alleles are background-dependent, and what genetic factors modulate their penetrance? We will use CRISPR/Cas9 to knock-out and knock-in alleles into targeted genes identified in aim 1 and will crossed these transgenic lines to the synthetic flies from aim 1 and the F1 progeny will be genotyped and phenotyped for Cr(VI) responses to identify modifiers.