Population genetic impacts of a changing ambient conditions on marcro-in-vertebrates with different life history strategies in running waters

预计在全球变暖的过程中，目前的河流流态将发生变化，洪水和枯水等极端情况的频率和强度将会增加。我们通过比较不同流态的河流-莱茵河和多瑙河(融雪)与莫泽尔河和主河(地下水)-以及三个具有不同生活史(高/低分散度和高/低抗旱性)的物种来研究这些变化的种群遗传效应。我们将在酶和DNA水平上使用标记。由于水温升高和遗传变异性降低，预计会出现基因类型的转变。前者反映了微进化的反应，使其能够在不断变化的环境条件下生存。后者是由当地和区域人口规模的极端波动以及洪水和干旱引发的反复瓶颈造成的。它限制了这种反应，并可能在目前的分布范围内降低种群的存活率。这项研究将允许对这两个过程进行评估。当地物种灭绝后的迁徙来源和重新定居方式将通过分子标记进行研究。水库和防波堤的避难所作用。将分析扩散的障碍。在特定温度或流动条件下占主导地位的基因类型将被提供给合作工作组进行生理研究和蛋白质组学分析。关于基因流动(扩散)的数量和距离以及现场观察到的种群密度的结果将被输入到建模项目中。

It is expected that in the course of global warming the present flow regimes of rivers will change and that extreme situations such as floods and low water will increase in frequency and intensity. We study the population genetic effect of these changes by comparing rivers of different flow regimes - Rhine and Danube (snowmelt) versus Moselle and Main (groundwater) - and three species with different life histories (high/low dispersion and high/low drought resistance). We will use markers on the level of enzymes and DNA. A shift of genotypes due to higher water temperatures and a decrease of genetic variability is expected. The former reflects the microevolutionary response and enables the survival under changing environmental conditions. The latter is caused by repeated bottle necks triggered by extreme fluctuations of local and regional population sizes accompanying floods and droughts. It limits this response and may reduce the survival of populations within their present distribution limits. This study will allow the assessment of these two processes. The sources of immigration and recolonisation ways after local extinctions will be studied by molecular markers. The role of reservoirs and barrages as refuges resp. impediment of dispersal will be analysed. Genotypes that dominate under certain temperature or flow regime will be provided for physiological studies and proteomic analyses to the co-operating working groups. Results on the amount and distance of gene flow (dispersal) as well as population densities observed in field will be input to the modelling project.