MARINE BIOTECHNOLOGY FELLOWSHIP: Biological Invasion and Genetic Intorgression of Exotic Mussels -- A Molecular Approach

海洋生物技术奖学金：外来贻贝的生物入侵和基因侵入——分子方法

• 批准号: 9023857
• 负责人: Jonathan Geller
• 金额: $ 8.4万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-15 至 1993-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9023857&HistoricalAwards=false
• 关键词: MARINE; BIOTECHNOLOGY; FELLOWSHIP; Biological; Invasion

Marine biological invasions are pervasive, and an understanding of the processes and mechanisms of invasions is important to our ability to manage and conserve marine resources. Biological invasions are also large.scale experiments in ecology and evolution, providing unique opportunities to study basic ecological and genetic processes in the world' oceans, including dispersal, recruitment, gene flow, and hybridization. This project will examine the temporal and spatial pattern of spread of an introduced mussel, and the extent of genetic introgression into populations of native mussels. This research will exploit the on.going incidental release of genetically distinct larvae of the exotic mussel, >Mytilus> >galloprovincialis>, to study the invasion of a species with pelagic larvae. >M.> >galloprovincialis> larvae are released into San Francisco Bay on a daily basis in the ballast water of Japanese ships. Our studies have shown that 4 x 10.6 mussel larvae may be released from a single ship. Because San Francisco is the only port in cent>>>>ral California large enough to receive ocean.going ships, all central California populations of >Mytilus> >galloprovincialis> likely stem from introduced population in San Francisco Bay. The PI will develop a set of primers (for mitochondrial and nuclear ribosomal genes) for the polymerase chain reaction (PCR) specific to invading Japanese >M.> >galloprovincialis> and to native >Mytilus> spp. Using PCR as an assay, the PI will then establish the distribution of Japanese >M.> >galloprovincialis> genotypes inside San Francisco Bay and in outlying bays and estuaries. This will elucidate intraregional patterns of dispersal of an invading species with pelagic larvae. Further, because nuclear genotypes have 2 sets of chromosomes, assay by PCR will detect hybrid genotypes, revealing genetic introgression into native populations. Combining mtDNA and nDNA analyses will allow detection of asymmetrical introgression. Until recently, the history of invasion by an exotic species could only be inferred from present day distribution, and little inferred about the >rate> of invasion. However, because PCR allows the amplification of DNA from preserved material, mussels collected (and preserved in museum collections) throughout the period of invasion on the North American west coast can analyzed using the primers developed in this project. In this way, it will be possible to reconstruct both the pattern and rate of invasion by >M.> >galloprovincialis>. This study, the first to apply molecular techniques to an ongoing marine invasion, will provide new insights in the processes of dispersal and introgression of alien genotypes during a biological invasion.

海洋生物入侵普遍存在，了解入侵的过程和机制对于我们管理和保护海洋资源的能力非常重要。 生物入侵也是生态学和进化方面的大规模实验，为研究世界海洋的基本生态和遗传过程（包括扩散、补充、基因流动和杂交）提供了独特的机会。 该项目将研究引进贻贝传播的时间和空间模式，以及基因渗入本地贻贝种群的程度。 这项研究将利用外来贻贝（>贻贝> >galloprovincialis>）遗传上不同的幼虫的持续偶然释放来研究远洋幼虫物种的入侵。 >M.> >galloprovincialis> 幼虫每天都会在日本船舶的压载水中释放到旧金山湾。 我们的研究表明，一艘船上可能会释放 4 x 10.6 贻贝幼虫。 因为旧金山是加州中部>>>加州中部唯一一个足够大的港口，可以接收远洋船舶，所以加州中部所有的>Mytilus> >galloprovincialis> 种群很可能源自旧金山湾的引进种群。 PI 将开发一套用于聚合酶链式反应 (PCR) 的引物（用于线粒体和核核糖体基因），该引物针对入侵的日本 >M.> >galloprovincialis> 和本地 >Mytilus> 属。 然后，PI 将使用 PCR 进行检测，确定日本 >M.> >galloprovincialis> 基因型在旧金山湾内以及外围海湾和河口的分布。 这将阐明带有远洋幼虫的入侵物种的区域内扩散模式。 此外，由于核基因型有 2 组染色体，PCR 检测将检测杂交基因型，揭示基因渗入到本地群体中。 结合 mtDNA 和 nDNA 分析将能够检测不对称基因渗入。 直到最近，外来物种的入侵历史只能从目前的分布来推断，而很少推断出入侵的>速率>。 然而，由于 PCR 允许从保存的材料中扩增 DNA，因此可以使用本项目开发的引物对在北美西海岸入侵期间收集的（并保存在博物馆收藏中的）贻贝进行分析。 通过这种方式，将有可能重建 >M.> >galloprovincialis> 的入侵模式和速率。 这项研究首次将分子技术应用于正在进行的海洋入侵，将为生物入侵期间外来基因型的扩散和渗入过程提供新的见解。