Molecular analysis of the hybrid genome of an invasive lineage of Cottus (pisces)

在过去，我们曾研究过欧洲牡蛎(Cottus Gobio)的系统地理，这种鱼可以被认为反映了自然种群的分布。分子分析使我们能够追踪莱茵河下游新进化的物种，该物种在形态和栖息地要求上与欧洲其他地方的物种不同。这一新物种目前正在向上游扩张，并与已建立的种群接触。这为现在研究不同时间范围内物种形成的自然实验提供了独特的机会。特别是，将有可能测试异地物种形成模型与共域物种形成模型的差异预测，以及新形成的与长期形成的杂交带的动态。我们计划分离特定参与新物种和祖先物种之间差异适应的基因组区域和基因。这将通过两种方法来完成，即系统地搜索特定于位点和群体的选择性扫描，以及通过微阵列方法来识别差异表达水平的基因。分子研究将得到关于来自不同地区和接触情况的动物之间的配偶选择的对照研究的补充。(P)

In the past we have studied the phylogeography of the Mühlkoppe (Cottus gobio) in Europe, a fish that can be considered to reflect a natural population distribution. Molecular analysis allowed us to trace a newly evolving species in the lower Rhine, which differs in morphology and habitat requirements from the species that occurs elsewhere in europe. This new species is currently expanding upstream and comes into contact with the established populations. This provides now the unique opportunity to study natural experiments in speciation at different time horizons. In particular, it will be possible to test differential predictions of allopatric versus sympatric speciation models, as well as the dynamics of newly formed versus long established hybrid zones. We plan to isolate genomic regions and genes that are specifically involved in differential adaptations between the new and the ancestral species. This will be done by two approaches, namely a systematic search for locus- and population-specific selective sweeps, as well as by microarray approach to identify genes with differential expression levels. The molecular studies will be complemented by controlled studies on mate choice between animals from different regions and contact situations. (p)