Positive Selektion in Drosophila melanogaster

在非洲的祖先物种范围内的黑腹果蝇种群与非洲以外的衍生种群有很大的差异。非洲以外的温带地区的殖民化发生在相对较近的时期（例如，大约5000年前在西欧）。利用搭便车效应，我们正在研究与这种“走出非洲”移徙有关的适应过程。也就是说，我们试图确定基因组中的沿着区域，其中核苷酸变异通过最近发生的有益取代（“选择性扫描”）而减少。具体来说，我们建议重新测序一个新收集的欧洲人口的D。使用下一代测序（NGS）技术对黑腹动物进行测序。再加上来自非洲，亚洲和北美的多态性数据，这将使我们能够使用贝叶斯方法全面推断该物种的近期人口统计历史。此外，我们将能够确定在D.黑腹果蝇种群迁移到非洲以外的新环境。特别是，我们调查了适应温带气候的遗传基础，通过精细定位耐寒性的数量性状基因座（QTL）的选择性扫描分析。

The Drosophila melanogaster populations in the ancestral species range in Africa are considerably differentiated from the derived populations outside Africa. The colonization of the temperate regions outside Africa occurred relatively recently (for instance, in western Europe about 5000 years ago). Using the hitchhiking effect, we are studying the adaptive process associated with this “out-of-Africa” migration. That is, we seek to identify regions along the genome in which nucleotide variation is reduced through the recent occurrence of beneficial substitutions (“selective sweeps”). Specifically, we propose to re-sequence a newly collected sample of a European population of D. melanogaster using next-generation sequencing (NGS) technology. Together with available polymorphism data from Africa, Asia and North America, this will allow us to infer the recent demographic history of this species in a comprehensive way using Bayesian methods. Furthermore, we will be able to identify the genes that have been the target of positive selection in the adaptation of D. melanogaster populations to their new environments outside Africa. In particular, we investigate the genetic basis of adaptation to the temperate climate by fine-mapping quantitative trait loci (QTL) for cold tolerance by selective sweep analysis.