Dissertation Research: Maladaptive Gene Flow and Counter Selection in a Blue Mussel Hybrid Zone

论文研究：蓝贻贝杂交区的适应不良基因流和反选择

基本信息

批准号：
0073846
负责人：
Thomas Hilbish
金额：
$ 0.81万
依托单位：
University of South Carolina at Columbia
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2000
资助国家：
美国
起止时间：
2000-06-01 至 2001-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0073846&HistoricalAwards=false
关键词：
Dissertation Research Maladaptive Gene Flow

项目摘要

0073846Hilbish & GilgIn Southwest England two mussel species, Mytilus edulis and M. galloprovincialis, interbreed and produce fertile hybrid offspring. Within this region individuals that are more closely related to M. galloprovincialis have better survival as adults than individuals that are more closely related to M. edulis. While you would predict that this advantage would result in M. galloprovincialis out-competing M. edulis and taking over the region, this hybrid zone has remained in the same location with the same proportions of the two species for at least 20 years. This study will determine what evolutionary factors are stabilizing the hybrid zone and offsetting the directional selection favoring M. galloprovincialis. Two potential factors are gene flow and natural selection favoring Mytilus edulis in the larval stage. It is possible that larvae that settle in the hybrid zone are predominantly coming from pure M. edulis populations and that this influx could offset natural selection. Larvae that settle in this region will be collected and their probable population of origin will be determined using genetic markers. This information will determine how far mussel larvae generally travel and in what direction. It is also possible that natural selection favoring M. edulis is occurring in the larval stage. This can be determined by raising larval mussels in the laboratory and determining changes in the genetic composition of the larvae.

0073846Hilbish & Gilg 在英格兰西南部，两种贻贝品种（贻贝和地中海贻贝）杂交并产生可育的杂交后代。在该区域内，与 M. galloprovincialis 关系更密切的个体成年后的存活率比与 M. edulis 关系更密切的个体更好。虽然您预计这一优势将导致 M. galloprovincialis 在竞争中击败 M. edulis 并占领该地区，但这个杂交区域至少 20 年以来一直保持在同一位置，两个物种的比例相同。这项研究将确定哪些进化因素正在稳定杂交区并抵消有利于 M. galloprovincialis 的方向选择。两个潜在因素是基因流和自然选择有利于幼虫阶段的贻贝。定居在混合区的幼虫可能主要来自纯的美味贻贝种群，这种流入可能会抵消自然选择。将收集定居在该地区的幼虫，并使用遗传标记确定其可能的起源种群。这些信息将确定贻贝幼虫通常移动的距离和方向。也有可能有利于美味贻贝的自然选择发生在幼虫阶段。这可以通过在实验室饲养贻贝幼体并确定幼体遗传组成的变化来确定。