Genetic dissection of complex traits in C. elegans

描述（由申请人提供）：拟议研究的广泛目标是线虫蠕虫和模式生物秀丽隐杆线虫中大量复杂和数量性状的遗传解剖，重点关注与人类健康相关的两类性状：对病原体和药物的反应。成功理解后生动物表型变异的遗传基础，将为设计人类和其他医学、生物学和农业生物的基因型-表型研究提供关键指导。所开发的方法和资源将广泛适用于秀丽隐杆线虫的其他表型。这些结果将提高我们对病原体易感性的基因和途径的理解，以及对化疗药物、驱虫药、杀虫剂和其他化合物的作用机制、耐药性和脱靶效应的理解。具体来说，我们将为这些性状开发高通量定量表型分析，并将其应用于上一个项目期间开发的遗传资源：大量高分辨率高级杂交重组自交系，来自布里斯托尔和夏威夷分离株的杂交，以及广泛具有序列变异特征的各种野生分离株。我们还将把这些分析应用于我们将开发的新遗传资源，作为拟议研究的一部分：我们将从野生分离物的最大多样性子集中建立和基因型定位群体。我们还将开发新的方法来快速鉴定任何起始亲本菌株的数量性状位点。我们期望这些努力能够产生：(i)一组具有良好特征的多种野生分离株和广泛有用的多亲本图谱，这些种群将与秀丽隐杆线虫研究界共享；（ii）适用于秀丽隐杆线虫和其他物种的新制图方法；(3)有大量的基因座可供进一步研究。然后，我们建议确定这些位点的基因和多态性，并研究这些性状的遗传结构，包括种群频率

DESCRIPTION (provided by applicant): The broad objective of the proposed research is the genetic dissection of a large number of complex and quantitative traits in the nematode worm and model organism C. elegans, with a focus on two classes of traits with relevance to human health: responses to pathogens and drugs. Success in understanding the genetic basis of phenotypic variation in a metazoan will provide critical guidance for the design of genotype-phenotype studies in humans and other organisms of medical, biological, and agricultural interest. The methods and resources developed will be broadly applicable to other phenotypes in C. elegans. The results will improve our understanding of the genes and pathways involved in susceptibility to pathogens, and in the mechanisms of action, resistance, and off-target effects of chemotherapeutics, anthelmintics, pesticides, and other compounds. Specifically, we will develop high-throughput quantitative phenotyping assays for these traits and apply them to genetic resources developed during the previous project period: a large set of high-resolution advanced intercross recombinant inbred lines from a cross between Bristol and Hawaii isolates, and a diverse collection of wild isolates extensively characterized for sequence variation. We will also apply these assays to new genetic resources that we will develop as part of the proposed research: we will build and genotype mapping populations from a maximally diverse subset of wild isolates. We will also develop new approaches for rapid identification of quantitative trait loci for any starting set of parent strains. We expect these efforts to produce:(i) a set of well-characterized diverse wild isolates and a broadly useful multiparent mapping population that will be shared with the C. elegans research community; (ii) new mapping methods applicable to C. elegans and other species; and (iii) a large set of loci for further investigation. We then propose to identify the genes and polymorphisms that underlie these loci, and to investigate the genetic architectures of the traits, including the population frequencies of the relevant alleles. We will confirm candidate genes and regions by using RNAi and transgenics to knock down or express genes in the appropriate strains. We will measure the frequencies of the identified alleles in the full diverse collection of wild isolates, and answer questions about rare vs. common alleles, additivity vs. dominance, and the role of genetic interactions. We expect to elucidate key principles of genetic architecture that will guide study design in C. elegans and other species. The pathways C. elegans uses to respond to biotic and abiotic stresses are conserved in humans and involved in a variety of diseases, including cancer and diabetes. Thus, we will leverage the power of the worm to better understand human biology. PUBLIC HEALTH RELEVANCE: Genetic factors underlie susceptibility to virtually every human disease, and much of current biomedical research is based on the expectation that identifying these factors is a crucial step in improving diagnosis, prevention, and treatment. Identification i difficult because the genetic basis of common disorders is complex, with disease susceptibility influenced by multiple genes. The proposed research will improve our understanding of genetic complexity and provide critical guidance for studies of the genetic basis of common human diseases. The proposed research will also provide insights into the genetic basis of two classes of traits with immediate health relevance-responses to pathogens and to drugs.