Collaborative Research: Organization of Nucleotide Diversity in the Inversions of Drosophila pseudoobscura

安德森9729144 该项目的研究目标是测试有关遗传的假设， 调节染色体变异的力量， 顺序称为反转。 第三个染色体倒位 Drosophila pseudosobscura的染色体在 进化生物学的文献超过50年。 他们有 被证明是一个非常有用的模型系统的研究地理 变异、自然选择、基因流和遗传漂变。 的倒置 似乎代表了适应性选择的一个明显的例子，因为它们在 频率与环境，形成经典的倾斜，并在一些 种群存在反转频率的季节性周期。 的 本建议的目的是确定选择如何作用于 倒位的遗传含量在D.拟暗 人口。 这项研究将区分不同的模型， 通过分析9个PCR扩增标记的核苷酸多样性进行选择 均匀分布在D.伪暗 的 9个标记将在D中测序。假暗菌菌株收集自 四个种群跨越一个反转频率梯度。 在过去的二十年里，分子进化的研究集中在 形成单个基因多样性的遗传力量， 考虑到如果选择维持连锁基因的组合， 染色体 这是一个悬而未决的问题， 基因组中的特定染色体由于选择而发生， 事故 反转提供了一种重要的机制来维持 遗传多样性分布在长距离的 染色体 该项目将提供有关遗传力的宝贵数据 调节自然界中基因组大片段的进化 人口。

Anderson 9729144 The research goals of this project are to test hypotheses about the genetic forces that modulate variation of chromosomal alterations that modify gene order known as inversions. The chromosomal inversions on the third chromosome of Drosophila pseudoobscura have figured prominently in the literature of evolutionary biology for more than fifty years. They have proven to be a very useful model system for studies of geographic variation, natural selection, gene flow, and genetic drift. The inversions seem to represent a clear case of adaptive selection because they vary in frequency with the environment, form classical clines, and in some populations there are seasonal cycles of inversion frequency. The objective of this proposal is to determine how selection acts on the genetic contents of inversions within and among D. pseudoobscura populations. This research will discriminate between various models of selection by analyzing nucleotide diversity of nine PCR amplified markers uniformly distributed on the third chromosome of D. pseudoobscura. The nine markers will be sequenced in D. pseudoobscura strains collected from four populations that span an inversion frequency cline. Studies of molecular evolution over the past two decades have focussed on the genetic forces that shape diversity of single genes and have not considered if selection maintains assemblages of linked genes on chromosomes. It is an open question whether the association of genes on particular chromosomes within the genome happened due to selection or accident. Inversions provide an important mechanism to maintain the association of genetic diversity distributed across long distances of chromosomes. This project will provide valuable data on the genetic forces that modulate the evolution of large segments of the genome in natural populations.