Analysis of Speciation by Complex Trait Mapping

描述(申请人摘要)：了解基因和分子 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，那些 定义物种分化的各个方面在 进化生物学。我们的目标是： I)发展轮回选择/回交(RS/B)作图方法 以及克隆复杂性状的基因--这种方法依赖于持续的选择 当回交所选产品时，用于所需的表型(例如，高) 重复到表型相反的品系(LOW)。最终产品应该是 基因组起源于低亲本的品系，但不在其附近或在其附近 属于高表型的基因座。标记的全基因组扫描 基因分型应该能够精确定位大多数控制基因座。 表型。我们计划开发这种方法，使用计算机模拟和 分析建模。该方法也适用于多组分的分析。 新生物种形成的动态以及物种的概念 分子水平(Ting et al.2000)。 II)该方法在果蝇性别分化中的应用 行为--所选择的特征是黑腹金龟强烈的性取向 来自津巴布韦的属于自己的类型(Z型)，而不是来自其他大陆的苍蝇 (M型)。选择将基于这样一个事实，即只有Z型男性才能成功 与纯Z雌性交配；选定的雄性将回交到M 女性。这项实验经过40代后，将创造60个复制品系 在决定Z型男性行为的基因座或其附近携带Z-衍生DNA； 在其他地方，他们将像M一样。20代和40代的苍蝇将是 利用待开发的DNA标记对三号染色体进行基因分型。我们希望 准确地定义总的遗传结构，并绘制出一些主要的 Z-男性基因座在30kb以内。在最后阶段，我们将开展 30株天然分离株与中国分离株候选基因的关联性研究 每个映射的区域。

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.