Transcriptional basis of cold adaptation in Drosophila melanogaster

果蝇（Drosophila melanogaster）最初是一种非洲热带物种。直到最近（在过去的15000年里），它才征服了像欧洲这样的新栖息地。显然，这种新的欧洲环境与物种起源有很大的不同，例如在平均温度和冬天的严酷程度和长度上。该项目旨在揭示在范围扩展到温带栖息地期间促进当地适应的基因。具体来说，我们对改变基因表达水平的基因组变化感兴趣。为了找到这些，我们计划将欧洲和非洲的苍蝇暴露在冷休克中，并使用全基因组微阵列测量它们的转录反应。表现出表达差异的基因可能是为了提高耐寒性而经历了调节适应的候选基因。此外，我们想研究这种适应性变化是否是顺式或反式调控突变的结果。使用具有均质基因组背景的果蝇将使我们能够解决这个问题。最后，我们希望通过利用黑腹龙源中可用的转基因工具，通过人工增加或减少基因的表达水平，从功能上测试候选基因的转录水平变化是否真的是导致耐寒性差异的原因。

The fruit fly Drosophila melanogaster is originally an Afro-tropical species. Only recently (within the last 15,000 years) has it conquered new habitats like Europe. Obviously, this novel European environment differs greatly from the species origin, e.g. in mean temperature and the severity and length of winter. This project aims at uncovering genes which contributed to local adaptation during the range expansion into temperate habitats. Specifically, we are interested in changes in the genome that altered levels of gene expression. To find these we plan to expose European and African flies to a cold shock and measure their transcriptional response using whole-genome microarrays. Genes that show expression differences are candidates that may have undergone regulatory adaptation in order to provide increased cold tolerance. Furthermore, we would like to investigate if such adaptive changes are the results of cis- or trans-regulatory mutations. The use of flies with homogenized genomic backgrounds will allow us to address this question. Finally, we would like to functionally test if changes in transcription level of candidate genes are actually causative of differences in cold tolerance by using the transgenic tools available in D. melanogaster, which allow us to artificially increase or decrease expression levels of genes.