The Molecular Basis of Local Adaptation in Arabidopsis thaliana

描述（由申请人提供）：当今生物学面临的最重要的挑战之一是理解遗传变异。了解基因型变异是如何转化为表型变异的，以及它是如何在种群中形成的，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研究拟南芥的开花时间来增加我们对适应性变异的分子遗传基础的理解。研究的重点是对低温的开花反应，即所谓的春化，这是植物用来确保在正确的时间、正确的季节开花的主要机制之一。该项目旨在描述这一特征变异的遗传结构，并将在分子水平上识别涉及的主要基因和等位基因。鉴定出的多态性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，绘制出在世界不同地区收集的植物之间负责变异的基因图谱。图谱绘制将结合传统的连锁图谱绘制方法和所谓的全基因组关联扫描，其中现代基因分型技术用于调查种群样本中的大量多态性，以确定在统计上与该性状相关的基因组区域。其次，分子遗传学将用于表征鉴定的等位基因和位点。第三，将分析所鉴定位点内部和周围的变异模式，以阐明位点的选择历史。

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.