Drosophila Molecular Population Genetics

将进行的三个实验解决了关于塑造种群遗传变异的力量的基本问题。果蝇是模式生物，因为它将被研究，并非常适合于分子方法。最近的研究表明，在基因组中遗传重组相对较少的区域，分子多态现象非常少。最有希望解释这一现象的理论是，有利的突变体偶尔会在种群中移动，消除缺乏重组的大片区域的多态。拟议中的实验试图测试这一理论的一些定量预测。另一个实验调查了多态是否是“进程伪基因”。由于这种类型的基因被认为没有功能，对这种基因的研究将给出基因组中不受自然选择力量影响的部分的重要基线数据。第三个实验旨在测试一种理论的预测，该理论解释了自然种群中可转座元件(DNA寄生虫)拷贝数的控制。这一理论和观察到的转座元件的分布预测，在果蝇的X染色体顶端附近将会有高水平的不等同交换。拟议中的实验将直接测量基因组这一区域不平等(异位)交换的频率。这些实验的结果应该会促进我们对各种重组和突变过程对立地变异的影响的理论理解。这一理论知识领域往往是解释人类和其他具有经济或基本利益的生物体中实际重要的和/或理论上有意义的遗传变异的基础。

The three experiments to be conducted address basic questions about the forces that shape genetic variation in populations. Drosophila is the model organism because it is will studied and highly suitable for molecular approaches. Recent work has revealed that there is remarkably little molecular polymorphism in regions of the genome that have relatively little genetics recombination. The most promising theory to account for this is that favorable mutants occasionally move through the population, removing polymorphisms in a large region that lacks recombination. The proposed experiments attempt to test some of the quantitative predictions of this theory. Another experiment investigates whether polymorphism is a "process pseudogene." Since this type of gene is thought to have no function, the study of such a gene will give important baseline data on a part of the genome that is "free" from the force of natural selection. The third experiment is designed to test a prediction of a theory that accounts for the containment of copy numbers of transposable elements (DNA parasites) in natural populations. This theory and the observed distributions of transposable elements predicts that there will be high levels of unequal crossing over near the tips of the X chromosome in Drosophila. The proposed experiments will directly measure the frequency of unequal (ectopic) exchange in this region of the genome. The results from these experiments should advance our theoretical understanding of the impact of various recombinational and mutational processes on standing variation. This theoretical area of knowledge is often the foundation for the interpretation of practically important and/or theoretically interesting genetic variation in humans and other organisms of economic or basic interest.