Genetic dissection of complex traits in C. elegans

描述(申请人提供)：拟议研究的广泛目标是对线虫和模式生物秀丽线虫的大量复杂和数量特征进行遗传解剖，重点关注与人类健康相关的两类特征：对病原体和药物的反应。成功地理解后生动物表型变异的遗传基础将为人类和其他具有医学、生物学和农业意义的生物的基因-表型研究的设计提供重要的指导。所开发的方法和资源将广泛适用于线虫的其他表型。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、驱虫剂、杀虫剂和其他化合物的作用、耐药性和非靶点效应的机制的理解。具体地说，我们将为这些性状开发高通量定量表型分析，并将它们应用于前一个项目期间开发的遗传资源：来自布里斯托尔和夏威夷分离物的大量高分辨率高级杂交重组自交系，以及以序列变异为广泛特征的各种野生分离物的集合。我们还将把这些分析应用于我们将作为拟议研究的一部分而开发的新的遗传资源：我们将从最大限度地多样化的野生分离物子集建立种群并绘制基因图谱。我们还将开发新的方法来快速识别任何一组亲本菌株的数量性状基因座。我们希望这些努力将产生：(I)一套特征良好的多样化野生分离物和广泛有用的多亲代作图群体，将与线虫研究界共享；(Ii)适用于线虫和其他物种的新作图方法；以及(Iii)一大组用于进一步研究的基因座。然后我们建议确定这些基因座背后的基因和多态，并调查这些性状的遗传结构，包括群体频率 相关的等位基因。我们将通过RNAi和转基因技术在适当的菌株中敲除或表达基因来确定候选基因和区域。我们将测量在完全不同的野生分离株集合中识别的等位基因的频率，并回答有关稀有与常见等位基因、加性与显性以及遗传相互作用的作用的问题。我们希望阐明基因结构的关键原则，这些原则将指导线虫和其他物种的研究设计。线虫用来响应生物和非生物压力的途径在人类中是保守的，并与包括癌症和糖尿病在内的各种疾病有关。因此，我们将利用蠕虫的力量来更好地了解人类生物学。

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.