Collaborative Research: Molecular Basis Of Novel Phenotypes Resulting From Interpopulation Hybridization

气候变化影响种群和物种的地理分布，并可能导致以前孤立的种群之间杂交的机会增加。杂交可以产生一系列的结果。最常见的是，杂交导致适应性丧失（杂交破坏），有效地减少了杂交并促进了新物种的形成。然而，偶尔，新的基因组合会给杂交物种带来生态优势，包括适应新的生态位。亲本群体的哪些属性可以预测杂交的结果？回答这个问题是这个项目的重点，并将为气候和生态变化对适应率和物种形成的影响提供新的见解。研究人员还将在伯奇水族馆开展新颖的公共非正式教育，并为圣地亚哥贫困社区的五年级学生提供海洋生物学的实践经验。预测杂交结果需要了解杂交表型的分子基础。该项目将对加利福尼亚虎脚类不同种群的杂交后代进行基因组分析。先前的研究表明，在杂交动物中，线粒体的能量产生经常被破坏。全基因组测序将用于确定线粒体性能正常与中断的杂交桡足动物群体之间的遗传差异；群体之间的分化将确定可能导致杂交崩溃的候选基因。结果将解决：a)杂交是否会导致整个基因组的广泛不相容，或者是否可以识别目标基因？b)在不同的种群间杂交中，相同的基因组区域是否导致杂交破裂？一个类似的方法将被用来检验改良杂交耐热性的基因组基础。什么样的基因相互作用使得一些杂交品种能够在对亲本种群都致命的温度下存活下来？从亲本群体之间的遗传或生态差异能否预测杂种的表现？

Climate change affects the geographic distribution of populations and species and can result in increased opportunities for hybridization between previously isolated populations. Hybridization can have a range of outcomes. Most frequently, hybridization results in loss of fitness (hybrid breakdown), effectively reducing interbreeding and promoting the formation of new species. Occasionally, however, novel combinations of genes yield ecological advantages to hybrids, including adaptation to new ecological niches. What attributes of parental populations predict the outcome of hybridization? Answering this question is the focus of this project, and will provide new insights into the effects of climate and ecological changes on adaptation rates and species formation. The researchers also will engage in novel public informal education at the Birch Aquarium and in hands-on experiences in marine biology for 5th grade students in underserved San Diego neighborhoods. Predicting hybridization outcomes requires an understanding of the molecular basis of hybrid phenotypes. This project will conduct genomic analyses of hybrids produced by crosses between divergent populations of the copepod Tigriopus californicus. Previous work has shown that energy production by mitochondria is frequently disrupted in hybrids. Whole genome sequencing will be used to determine genetic differences between groups of hybrid copepods with normal versus disrupted mitochondrial performance; differentiation between the groups will identify candidate genes that are potentially responsible for hybrid breakdown. Results will address: a) Does hybridization result in widespread incompatibilities across the genome, or can targeted genes be identified? b) Are the same genomic regions responsible for hybrid breakdown in different interpopulation crosses? A similar approach will be used to examine the genomic basis of improved hybrid thermal tolerance. What genetic interactions allow some hybrids to survive temperatures that are lethal to both parental populations? Is hybrid performance predictable from genetic or ecological differences between parental populations?