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

海洋生物入侵无处不在， 入侵的过程和机制对我们来说很重要 管理和保护海洋资源的能力。 生物 入侵也是大规模的生态学实验， 进化，提供独特的机会，学习基础 生态和遗传过程，包括 扩散、招募、基因流动和杂交。 这 项目将研究传播的时间和空间模式 以及基因渗入的程度 变成本地贻贝的种群 这项研究将利用正在进行的附带释放的 基因上不同的外来贻贝的幼虫，>贻贝> > galloprovincialis>，研究一个物种的入侵， 浮游幼虫 > M.> > galloprovincialis>幼虫被释放到 弗朗西斯科湾每天在压载水的 日本船。 我们的研究表明4x10.6的贻贝 幼虫可以从一艘船上释放。 因为旧金山弗朗西斯科 是加州中部唯一一个大到足以接收 远洋船只，所有加州中部的>贻贝>种群 > galloprovincialis>可能源于San 弗朗西斯科湾。 PI将开发一组引物（用于线粒体和 核核糖体基因）进行聚合酶链反应（PCR） 具体到入侵日本人> M.> > galloprovincialis>和本地 >贻贝属>种属 使用PCR作为检测方法，PI将建立 日本人的分布> M.> > galloprovincialis> genotypes 在旧金山弗朗西斯科湾和外围海湾和河口。 这将阐明一个区域内的扩散模式， 有浮游幼虫的入侵物种。 此外，由于核 基因型有2套染色体，PCR检测将检测 杂交基因型，揭示了遗传渗入到本地 人口。 结合mtDNA和nDNA分析将允许 检测不对称基因渗入。 直到最近，外来物种入侵的历史 只能从今天的分布推断， 关于“入侵率”的推断。 由于PCR允许 从保存的材料贻贝中扩增DNA 收集（并保存在博物馆收藏）在整个 北美西海岸的入侵时期可以分析 使用本项目开发的引物。 这样就 将有可能重建的模式和速度， 入侵由M。> galloprovincialis>. 这项研究是第一个将分子技术应用于正在进行的 海洋入侵，将提供新的见解的过程中， 外来基因型的扩散和渐渗 生物入侵

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.