Analysis of Speciation by Complex Trait Mapping

描述（申请人的摘要）：了解遗传和分子生物学 复杂性状的基础是一项具有挑战性的任务。在所有复杂的特征中， 定义物种分化的各个方面， 进化生物学我们的目标是： I）用于作图的轮回选择/回交（RS/B）方法的开发 和克隆复杂性状的基因-该方法依赖于不断的选择 对于所需的表型（例如，高），同时回交选定的产品 回归到相反表型的品系（低）。最终产品应当 是其基因组来自低亲本的品系，除了在或接近 属于High表型的基因座。标记的全基因组扫描 基因型应该允许控制大多数基因座的精确定位。 表型。我们计划使用计算机模拟和 分析建模该方法也适用于分析 新生物种形成的动力学，以及物种的概念， 分子水平（Ting et al. 2000）。 II）该方法在果蝇性别种族分化中的应用 行为-所选择的特征是D的强烈的性偏好。melanogaster 从津巴布韦为自己的类型（Z型），从其他大陆苍蝇 （M型）。选择将基于这样一个事实，即只有Z型男性成功地 与纯Z雌性交配;然后选择雄性与M回交 女性经过40代的实验，将创造60个复制系 在决定Z型男性行为的基因座处或附近携带Z衍生的DNA; 在其他地方，它们将是M型的。第20代和第40代的苍蝇将 使用待开发的DNA标记对染色体III进行基因分型。我们期望 准确地定义总的遗传结构，并绘制一些主要的 Z-雄性位点在30 kb内。在最后阶段，我们将执行 30个自然分离株与来自 每个映射区域。

DESCRIPTION (Applicant's Abstract): Understanding the genetic and molecular bases of complex traits is a challenging task. Among all complex traits, those that define aspects of species differentiation hold a special place in evolutionary biology. Our aims are: I) Development of the recurrent selection/backcross (RS/B) method for mapping and cloning genes of complex traits - The method relies on continual selection for the desired phenotype (say, High) while backcrossing the selected products recurrently to lines of the opposite phenotype (Low). The final product should be lines whose genomes are derived from the Low parent, except at or near loci pertaining to the High phenotype. Whole genome scanning of marker genotypes should allow precise mapping of the majority of loci controlling the phenotype. We plan to develop this method using both computer simulations and analytical modeling. The method is also applicable to the analysis of the dynamics of nascent speciation, as well as the concept of species at the molecular level (Ting et al. 2000). II) Application of the method to Drosophila racial differentiation in sexual behaviors - The trait chosen is the strong sexual preference of D. melanogaster from Zimbabwe for their own type (Z type), over flies from other continents (M-type). Selection will be based on the fact that only Z-type males succeed in mating with pure Z females; selected males will then be backcrossed to M females. The experiment, after 40 generations, will create 60 replicate lines carrying Z-derived DNA at or near loci that determine Z-type male behavior; elsewhere, they will be M-like. Flies from Generation 20 and 40 will be genotyped over Chromosome III using DNA markers to be developed. We expect to define the total genetic architecture accurately and to map some of the major Z-maleness loci to within 30 kb. In the final phase, we will carry out association studies between 30 natural isolates and the candidate genes from each mapped region.