The Molecular Basis of Local Adaptation in Arabidopsis thaliana

描述(申请人提供)：今天生物学面临的最重要的挑战之一是弄清楚遗传变异的意义。了解基因变异如何转化为表型变异及其在种群中的结构是我们理解进化的基础，对人类健康以及农业和保护具有巨大的实际意义。该项目的长期目标是通过对拟南芥开花时间的研究，增加我们对适应性变异的分子遗传学基础的理解。重点是开花对低温的反应，即所谓的春化，这是植物用来确保它们在正确的时间，在正确的季节开花的主要机制之一。该项目试图描述这一特征的潜在变异的遗传结构，并将在分子水平上确定涉及的主要基因和等位基因。已识别的多态的适应性意义将在田间试验中确定。该项目有三个具体目标：第一，绘制导致世界不同地区采集的植物之间差异的基因图谱。作图将使用传统的连锁作图方法和所谓的全基因组关联扫描相结合的方式进行，在这种扫描中，现代基因分型技术被用来调查人群样本中的大量多态，以便识别似乎在统计上与该性状相关的基因组区域。其次，将使用分子遗传学来鉴定已识别的等位基因和基因座。第三，将分析已识别的基因座及其周围的变异模式，以阐明在这些基因座上进行选择的历史。 项目简介：当今生物学面临的最重要挑战之一是了解个体之间的遗传变异如何转化为我们可以看到或测量的变异，比如人类的血压，或者大米的耐旱性。这个项目的目的是通过研究模式植物拟南芥(Arabiopsis Thaliana)的开花时间，增加我们对适应性自然变异遗传学基本原理的理解。重点是开花对低温的反应，即所谓的春化，这是植物用来确保它们在正确的时间，在正确的季节开花的主要机制之一。

DESCRIPTION (provided by applicant): One of the most important challenges facing biology today is making sense of genetic variation. Understanding how genotypic variation translates into phenotypic variation and how it is structured in populations is fundamental to our understanding of evolution, and has enormous practical implications for human health as well as for agriculture and conservation. The long-term objective of this project is to increase our understanding of the molecular genetic basis for adaptive variation by studying flowering time in A. thaliana. The focus is on the flowering response to cold temperatures, so-called vernalization, which is one of the major mechanisms plants use to ensure that they flower at the right time, during the right season. The project seeks to describe the genetic architecture underlying variation for this trait, and will identify, at the molecular level, the major genes and alleles involved. The adaptive significance of the identified polymorphisms will be determined in field trials. The project has three specific aims: First, to map the genes responsible for variation between plants collected in different parts of the world. The mapping will be done using a combination of traditional linkage mapping methods and so-called genome-wide association scans, in which modern genotyping technology is used to survey massive amounts polymorphisms in population samples in order to identify genomic regions that appear to be statistically associated with the trait. Second, molecular genetics will be used to characterize the identified alleles and loci. Third, the pattern of variation in and around identified loci will be analyzed in order to elucidate the history of selection on the loci. Project Narrative: One of the most important challenges facing biology today is understanding how genetic variation between individuals translates into variation we can see or measure, like blood pressure in humans, or drought tolerance in rice. The goal of this project is to increase our understanding of the general principles that underlie the genetics of adaptive natural variation by studying flowering time in the model plant thale cress (Arabidopsis thaliana). The focus is on the flowering response to cold temperatures, so-called vernalization, which is one of the major mechanisms plants use to ensure that they flower at the right time, during the right season.