EAGER: RNA Polymerase V as a Novel Capacitor of Phenotypic Variation in Arabidopsis thalian

智力优势。 生物系统对遗传和环境的扰动具有显著的鲁棒性。先前的研究确定了伴侣HSP 90作为维持表型稳健性的重要机制。HSP90扰动降低了鲁棒性，并揭示了植物，苍蝇，鱼类和酵母中的神秘遗传变异。HSP 90具有隐蔽和释放遗传变异的特性，被称为表型变异的电容器。另一个推定的新电容器的表型变异现已确定在拟南芥：RNA聚合酶V。像HSP 90，Pol V保持表型的鲁棒性。而HSP 90主要在蛋白质折叠中起作用，Pol V在RNA指导的DNA甲基化、沉默转座子、串联重复序列和基因间区域中起作用，并驱动rDNA的压缩。作为一个真正的电容器，功能性Pol V应该隐藏遗传变异。在目标1中，将使用一种创新的方法来测试功能性Pol V是否隐藏遗传变异。由于Pol V影响染色质状态和基因组稳定性，因此Pol V突变体中增加的表型变异可能由不同的、潜在可遗传的表观遗传或遗传状态引起。如果为真，则选择应该修复这些表型。在目标2中，将通过繁殖野生型和pol V突变体的具有极长和极短茎的个体幼苗，然后记录一系列表型以确定选择反应来进行选择实验。 在目的3中，将通过在具有降低水平的Pol V和HSP 90的植物中进行全基因组表达分析来评估HSP 90和Pol V之间的机制重叠的程度。Pol V作为功能独特的电容器的拟议表征首次提供了识别与稳健性降低相关的常见分子特征的机会，无论是原因还是后果。该项目解决了有争议的，但基本的，表型电容的概念，旨在建立Pol V作为一种新的电容器在A。thaliana.它通过测试功能不同的电容机制在共同的分子特征（在这种情况下是在染色质）上收敛的假设，开辟了新的领域。该项目为研究生和本科生级别的学生培训提供了机会。 代表性不足的少数民族学生将参加学术研究，通过正在进行的暑期实习计划开发和PI运行。 与新墨西哥州大学和莫尔豪斯学院的教师合作，将使华盛顿大学基因组科学教师能够访问少数民族服务机构，并回访西雅图。这些访问旨在扩大教师和他们的研究生，谁将是明天的教师的研究视野。

Intellectual Merit. Biological systems are remarkably robust to genetic and environmental perturbations. Previous research identified the chaperone HSP90 as an important mechanism in maintaining phenotypic robustness. HSP90 perturbation decreases robustness and reveals cryptic genetic variation in plants, flies, fish, and yeast. Due to its property of concealing and releasing genetic variation, HSP90 has been named a capacitor of phenotypic variation. Another putative novel capacitor of phenotypic variation has now been identified in Arabidopsis thaliana: RNA polymerase V. Like HSP90, Pol V maintains phenotypic robustness. Whereas HSP90 functions primarily in protein folding, Pol V functions in RNA-directed DNA methylation, silencing transposons, tandem repeats, and intergenic regions, and drives compaction of rDNA. As a bona fide capacitor, functional Pol V should conceal genetic variation. In Aim 1, an innovative approach will be used to test whether functional Pol V conceals genetic variation. As Pol V affects chromatin states and genome stability, the increased phenotypic variation in pol V mutants may be caused by different, potentially heritable epigenetic or genetic states. If true, selection should fix these phenotypes. In Aim 2, selection experiments will be conducted by propagating individual seedlings with extremely long and short stems for wild-type and pol V mutants and then documenting a range of phenotypes to determine the selection response. In Aim 3, the extent of mechanistic overlap between HSP90 and Pol V, will be assessed by conducting a whole-genome expression analysis in plants with reduced levels of Pol V and HSP90. The proposed characterization of Pol V as a functionally distinct capacitor offers, for the first time, the opportunity to identify common molecular features that are associated with decreased robustness, either as causes or consequences. This project addresses the controversial, yet fundamental, concept of phenotypic capacitance by aiming to establish Pol V as a novel capacitor in A. thaliana. It breaks new ground by testing the hypothesis that functionally distinct capacitance mechanisms converge at common molecular features, in this case at chromatin.Broader Impacts. The project offers opportunities for student training at both graduate and undergraduate levels. Underrepresented minority students will participate in academic research, through an ongoing summer internship program developed and run by the PI. Collaborations with faculty at the University of New Mexico and Morehouse College will enable visits of University of Washington Genome Sciences faculty to both minority serving institutions and return visits to Seattle. These visits are aimed at expanding research horizons for both faculty and their graduate students, who will be tomorrow's faculty members.