Exploring Genomic Targets of Selection during Parallel Niche Expansions

许多物种被引入新的栖息地，但只有一小部分存活下来并变得有害。该项目将探索物种从盐水栖息地入侵淡水湖和水库后经历自然选择的基因，并提出以下问题：在重复和独立的入侵中是否涉及相同的基因？该研究以一种小型甲壳类动物——桡足类鹦鹉螺（Eurytemora affinis）为模型，这种动物是通过船舶运输引入北美淡水系统的。该项目(1)将确定与淡水适应直接相关的基因组区域；(2)分析在独立入侵中是否涉及共享的遗传机制。基因或基因组中的位置将通过定量性状位点（QTL）定位来确定，使用标准和高分辨率方法。这些分析将对多个独立的入侵进行，以确定是否涉及相同的基因组区域。生物入侵对生态系统的完整性、商业和公众健康产生了巨大的影响，仅在美国每年就造成约1500亿美元的经济损失。五大湖受到严重影响，成为内陆入侵的主要通道。了解在入侵过程中经历选择的基因和特征，将有助于了解为什么只有某些物种会入侵，从而有可能提供阻止它们入侵的方法。该项目还将帮助培养本科生和研究生。

Many species are introduced into new habitats, but only a small percentage survive and become harmful. This project will explore the genes that undergo natural selection after a species invades freshwater lakes and reservoirs from saline habitats asking: Are the same genes involved during repeated and independent invasions? The study uses as a model a small crustacean, the copepod Eurytemora affinis, that was introduced to freshwater systems in North America through ship traffic. The project (1) will identify genomic regions that are directly linked to freshwater adaptation and (2) analyze whether shared genetic mechanisms might be involved across independent invasions. The genes, or locations in the genome will be identified through quantitative trait loci (QTL)-mapping, using both standard and high-resolution approaches. These analyses will be performed for multiple independent invasions to determine whether the same genomic regions are involved.Biological invasions have enormous impacts on ecosystem integrity, commerce, and public health, with economic costs of approximately $150 billion per year in the US alone. The Great Lakes are heavily affected, and serve as a major corridor for inland invasions. Knowing the genes and traits that undergo selection during invasions would provide insights into why only certain species invade, potentially providing the means to stop them. The project will also help train undergraduate and graduate students.