Genetic Structure of Sea Urchin Populations Across a Biogeographic Boundary

9415669 Burton项目摘要本研究的总体研究目标是确定温带水域海胆的两个同属物种的自然种群的遗传结构：(1)紫海胆(Strongylotrotus Puratus)和(2)红海胆(S.franciscanus)。除了种群遗传学调查外，这项研究还将在18个月内对几个海胆种群进行三次采样，以确定特定大小的等位酶频率，以评估种群间基因流动的当代水平。这项研究试图填补理解海洋无脊椎动物种群结构的两个重要问题：1)生物地理边界在多大程度上反映在跨越边界的物种的遗传结构中？2)遗传分化模式是用特定种群间的基因流动障碍、正在进行的自然选择还是这些过程的某种组合来最好地解释？大多数海洋种群对当地人口招募新兵的来源和移民在人口之间流动的可行性的分析知之甚少。然而，这样的理解对于有效管理海洋生物资源是至关重要的。这项研究的数据将用于启动解决上述问题所需的密集人口遗传分析。对于红海胆来说，这种分析尤其及时，它目前在加利福尼亚州海岸的大部分地区面临着巨大的捕食压力--来自加利福尼亚州中部的海獭和其他地区的人类捕鱼活动。Franciscanus现在支持加州海岸最有价值的无脊椎动物渔业之一。

9415669 Burton PROJECT ABSTRACT The overall research objective of the proposed study is to determine the genetic structure of natural populations of two congeneric species of temperate water sea urchins: (1) the purple urchin, Strongylocentrotus purpuratus, and (2) the red urchin, S. franciscanus. In addition to the population genetic survey, the study will determine size- specific allozyme frequencies in several populations of sea urchins sampled three times over an eighteen month period in order to asses contemporary levels of interpopulation gene flow. The research seeks to fill two important questions in the understanding of the population structure of marine invertebrates: 1) To what extent are biogeographic boundaries reflected in the genetic structure of species which span the boundaries? and 2) Are patterns of genetic differentiation best explained by impediments of gene flow among specific populations, by ongoing natural selection, or by some combination of these processes? Analysis of sources of recruits to local populations and the viability of immigrants moving between populations is poorly understood in most marine populations. Yet such an understanding is essential to the effective management of marine biotic resources. The data from this study will be used to initiate an intensive population genetic analysis required to address the issues mentioned above. Such analyses are especially timely in the case of the red urchin, which currently faces intense predation pressure over much of the California Coast - from sea otters in central California and from human fishing activities in other regions. S. franciscanus now supports one of the most valuable invertebrate fisheries on the California coast.