Genetic Structure of Sea Urchin Populations Across a Biogeographic Boundary

小行星9415669 项目摘要 拟议研究的总体研究目标是确定两个同属种的温带水域海胆自然种群的遗传结构：（1）紫色海胆，Strongylocentrotus purpuratus，和（2）红色海胆，S。弗朗西斯卡努斯。 除了群体遗传调查外，该研究还将确定在18个月内取样三次的几个海胆群体中大小特异性等位酶的频率，以评估当代群体间基因流动的水平。 该研究试图解决两个重要的问题，在理解海洋无脊椎动物的种群结构：1）在多大程度上是地理边界反映在物种的遗传结构跨越边界？ （2）遗传分化的模式是否可以用特定种群间基因流动的障碍、持续的自然选择或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种群的新兵来源和种群间迁移的移民的生存能力的分析知之甚少。 然而，这种认识对于有效管理海洋生物资源至关重要。 本研究的数据将用于启动解决上述问题所需的密集群体遗传分析。 这种分析在红海胆的情况下特别及时，目前在加州海岸的大部分地区面临着强烈的捕食压力-来自加州中部的海獭和其他地区的人类捕鱼活动。 S. franciscanus现在是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.