USING DISEQUILIBRIUM MAPPING TO DISSECT COMPLEX TRAITS

致病DNA多态的连锁不平衡作图 大样本中腹部和胸膜刷毛数量的变化 将对野生捕获的果蝇进行检测，以检测一些 假设：i)候选基因的DNA多态是否有助于 连续字符的标准变异？Ii)频率是多少？ 以及这些多态的影响(包括上位性)，III)什么是 植物体内标准变异的分子本质(编码与调控) 数量性状？，iv)是通过关联作图识别的因素 与QTL定位一致的是关联作图 能够在人类中有效地用于识别多态 哪些因素会导致复杂的疾病表型？评估 不平衡图谱对自然种群的适用性是至关重要的 如果我们希望这样的研究成为识别人类疾病的模式 导致基因多态。 为了检测DNA多态与遗传 对立度变化有很小影响的因素 数量字符必须为大量的个体打字 通过候选基因区域的大量多态DNA标记。 该项目关注三个候选基因，Delta、Notch和Enhancer 如果分裂，这些是发展的核心重要性 周围神经系统(刷毛是感受器)，特别是 在分子水平上得到了很好的表征。打字将通过以下方式完成 首先对每个候选基因上的20个等位基因进行测序以确定 基因来识别所有可能影响 刷毛编号。然后，设计等位基因特异性寡核苷酸，并 杂交到高密度膜上，长的PCR产物来自 大约有4000只野生捕获的个体被发现。杂交 序列寡核苷酸探测的模式允许每个个体 对大量多态位点进行基因分型。数据将是 检测多态DNA位点与基因变异之间的关系 刷毛数量，以及包含具有显著关联性的站点的区域 将进一步分类为饱和度，以确定候选原因 多态现象。候选原因多态的集合将允许 以上假设要直接解决。

Linkage disequilibrium mapping of DNA polymorphisms that contribute to variation in abdominal and steronpleural bristle number in large samples of wild caught Drosophila will be carried out in order to test a number of hypotheses: i) Do DNA polymorphisms at candidate genes contribute to standing variation in continuous characters?. ii) What are the frequencies and effects (including epistasis) of these polymorphisms, iii) What is the molecular nature (coding versus regulatory) of standing variation in quantitative traits?, iv) Are factors identified by association mapping consistent with those identified by QTL mapping, v) Is association mapping capable of being used effectively in humans to identify polymorphisms which contribute to complex disease phenotypes? Assessing the applicability of disequilibrium mapping to natural populations is crucial if we wish such studies to serve as a model for identifying human disease causing polymorphisms. In order to detect associations between DNA polymorphisms and genetic factors contributing a small fraction to standing variation in a quantitative character a large number of individuals must be typed for a large number of polymorphic DNA markers through a candidate gene region. This project focuses on three candidate genes, Delta, Notch, and Enhancer if Split, which are of central importance in the development of the peripheral nervous system (bristles are sensilla), and are particularly well characterized at the molecular level. Typing will be accomplished by first sequencing twenty alleles at each of the candidate genes to identify genes to identify all common polymorphisms that could potentially affect bristle number. Then, allele specific oligonucleotides are designed and hybridized to high density membranes on which long PCR products from approximately 4000 wild caught individuals are spotted. Hybridization patterns over sequential oligonucleotide probings allows each individual to be genotyped for a large number of polymorphic sites. Data will be examined for associations between polymorphic DNA sites and variation in bristle number, and regions containing sites with significant associations will be further typed to saturation to identify candidate causative polymorphisms. The set of candidate causative polymorphism will allow the above hypotheses to be directly addressed.