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

海洋生物入侵无处不在，了解入侵的过程和机制对我们管理和保护海洋资源的能力非常重要。生物入侵也很大。生态学和进化的规模实验，为研究世界海洋的基本生态和遗传过程提供了独特的机会，包括扩散，招募，基因流动和杂交。本项目将研究引进贻贝传播的时空格局，以及遗传渗入本地贻贝种群的程度。本研究将利用这一方法。偶然释放外来贻贝>Mytilus> >galloprovincialis>基因不同的幼虫，以研究一种具有远洋幼虫的物种的入侵。> M。日本船只的压载水中每天都有加洛布氏夜蛾>幼虫被释放到旧金山湾。我们的研究表明，一艘船可以释放4 × 10.6个贻贝幼虫。因为旧金山是唯一的港口在加利福尼亚北部>>>>大到足以接收海洋。在船只上，所有加利福尼亚中部的>Mytilus> >galloprovincialis>可能都来自旧金山湾的引进种群。PI将开发一套用于入侵日本bbbbm特异性聚合酶链反应（PCR）的引物（用于线粒体和核糖体基因）。利用PCR作为检测方法，PI将建立日本>m的分布。三藩市湾内及外围海湾及河口>基因型。这将阐明入侵物种与远洋幼虫的区域内扩散模式。此外，由于核基因型有两组染色体，PCR检测将检测到杂交基因型，揭示遗传渗入到本地群体。结合mtDNA和nDNA分析可以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现在的分布推断出来，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，因此在北美西海岸入侵期间收集的贻贝（并保存在博物馆藏品中）可以使用本项目开发的引物进行分析。这样，就有可能重建b> M的入侵模式和入侵速率。> > galloprovincialis >。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。

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.