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结果。 最常见的情况是，杂交会导致适应性丧失（杂交种崩溃），有效地减少了杂交，促进了新物种的形成。然而，有时候，新的基因组合会给杂种带来生态优势，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？解决这个问题是该项目的重点，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。研究人员还将在桦树水族馆进行新颖的公共非正式教育，并为圣地亚哥服务不足社区的五年级学生提供海洋生物学方面的实践经验。预测杂交结果需要了解杂交表型的分子基础。该项目将对桡足类加州虎足虫不同种群间杂交产生的杂种进行基因组分析。 先前的研究表明，线粒体的能量生产在杂交中经常受到干扰。 全基因组测序将用于确定具有正常线粒体性能与破坏线粒体性能的杂交桡足类组之间的遗传差异;组之间的差异将确定可能导致杂交失败的候选基因。结果将解决：a）杂交是否会导致基因组中广泛的不相容性，或者是否可以识别靶基因？B）在不同的种群间杂交中，是否有相同的基因组区域导致杂种的崩溃？ 一个类似的方法将被用来检查基因组的基础上提高杂交耐热性。 是什么样的遗传相互作用使一些杂交种在对双亲都是致命的温度下生存下来？ 杂交性能是否可从亲本种群之间的遗传或生态差异中预测？

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?