DISSERTATION RESEARCH: Effects of environmental stress on multiple generations of interpopulation hybridization.

论文研究：环境胁迫对多代群体间杂交的影响。

• 批准号: 0709775
• 负责人: Suzanne Edmands
• 金额: $ 1.2万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0709775&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Effects; environmental; stress

It is well established that interpopulation hybrids can experience enhanced fitness in the first generation, followed by depressed fitness in the second generation. Some evidence suggests hybrid fitness problems can be repaired in later generations, and that hybrids may be favored under environmental stress. This study uses the intertidal copepod Tigriopus californicus to assess hybridization over multiple generations in both benign and stressful conditions (high salinity). Experimental hybrid populations will be maintained for up to 17 months and assayed for genetic, morphometric and fitness components every two generations. Tigriopus' short generation time, ease of husbandry and abundance of population-specific molecular markers make it a particularly tractable system for this type of experiment.Results will test the specific hypothesis that hybridization can create genetic variants that are favored under environmental stress, and will help to elucidate the role of hybridization in the formation of new species. This work is also directly relevant to current concerns about the impacts of invasive species mixing with native populations, or farmed organisms mixing with wild populations. Using the Tigriopus model system allows the effects of benign vs. stressful conditions to be assessed in a rigorous fashion that would be difficult to achieve for most species of concern. Additionally, this project supports opportunities for undergraduate research and training at a university that serves a broad and diverse urban area.

种群间杂交种的适应度在第一代提高，在第二代降低。一些证据表明，杂交的适应性问题可以在后代中得到修复，而且杂交可能在环境压力下更受青睐。本研究使用潮间带桡足动物加利福尼亚虎足来评估在良性和高盐度条件下的多代杂交。实验杂交种群将维持17个月，并每隔两代进行遗传、形态测定和适应性成分分析。虎爪鱼世代时间短、易于饲养和丰富的群体特异性分子标记使其成为一种特别易于处理的实验系统。结果将验证杂交可以产生在环境胁迫下有利的遗传变异的特定假设，并将有助于阐明杂交在新物种形成中的作用。这项工作也直接关系到目前对入侵物种与本地种群混合的影响，或养殖生物与野生种群混合的影响。使用Tigriopus模型系统，可以以严格的方式评估良性与压力条件的影响，这对于大多数物种来说是难以实现的。此外，该项目还为大学的本科生研究和培训提供了机会，该大学服务于广泛而多样化的城市地区。