DISSERTATION RESEARCH: Invasion Risk in the Great Lakes: Estimating Propagule Pressure with Molecular Tools

摘要研究：五大湖的入侵风险：用分子工具估计繁殖压力LodgeDEB-0308934船舶压载水中运输的生物的生物入侵是环境退化的日益严重的原因，也是社会经济成本的重要来源。在初步研究中，P.I.采用了概率模型来估计繁殖压力带来的入侵风险，并从五大湖船舶压载水的样本中列举了成年生物。虽然无脊椎动物休眠阶段的入侵风险通常被认为是相当大的，但由于从形态特征识别休眠卵的技术难度，尚未对其进行量化。因此，这项研究的目标是通过结合分子和统计技术来识别和计数样本中的休眠卵子。评估这种方法可行性的初步研究表明，繁殖压力的高质量定量估计可以通过四个步骤获得：(1)提取核和线粒体DNA；(2)利用变性梯度凝胶电泳法分离基因序列；(3)基于基因序列识别分类群；(4)用统计模型估计物种的相对丰度。拟议的研究将使用这种方法来估计20艘船的传播压力，并进行入侵风险评估。

AbstractDISSERTATION RESEARCH: Invasion Risk in the Great Lakes: Estimating Propagule Pressure with Molecular ToolsLodgeDEB-0308934Biological invasions by organisms transported in ship ballast water are an increasing cause of environmental degradation and a significant source of economic costs to society. In preliminary research, the P.I. have adapted probabilistic models to estimate invasion risk from propagule pressures, and enumerated adult organisms from samples of Great Lakes ship ballast water. Though invasion risk from resting stages of invertebrates is generally believed to be considerable, it has not yet been quantified due to the technical difficulty of identifying resting eggs from morphological characters. Thus, the goals of this research are to identify and enumerate resting eggs in samples through a combination of molecular and statistical techniques. Pilot studies to assess the feasibility of this approach indicated that high-quality quantitative estimates of propagule pressure can be obtained through a four step process: (1) extraction of nuclear and mitochondrial DNA; (2) separation of gene sequences using denaturing gradient gel electrophoresis; (3) identification of taxonomic groupings based on gene sequences; and (4) estimation of species relative abundance with statistical models. The proposed research will use this method to provide estimates of propagules pressure from 20 ships and to conduct risk assessments of invasion.