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

摘要论文研究：五大湖的入侵风险：用分子工具估算传播体压力船舶压载水中生物的入侵是造成环境退化的一个日益严重的原因，也是社会经济成本的一个重要来源。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样本中列举了成年生物。虽然一般认为无脊椎动物休眠阶段的入侵风险是相当大的，但由于从形态学特征识别休眠卵的技术困难，尚未对其进行量化。因此，本研究的目标是通过分子和统计技术的结合来识别和枚举样本中的休眠卵。评估该方法可行性的初步研究表明，繁殖体压力的高质量定量估计可以通过四个步骤获得：(1)提取细胞核和线粒体DNA；(2)变性梯度凝胶电泳分离基因序列；(3)基于基因序列的分类类群鉴定；(4)用统计模型估计物种相对丰度。拟议的研究将使用这种方法对20艘船的传播压力进行估计，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.