Molecular Basis of F2 Hybrid Breakdown

地理上与世隔绝的种群随着时间的推移在基因上发生分化，最终可能成为新物种。在这一过程的早期，当种群仍然可以杂交时，遗传不亲和性往往会导致种群间杂交的适合度丧失。这项拟议的研究使用海洋桡足类动物Tigriopus calforNicus来研究杂交后代丧失适合度的分子机制。最近的研究表明，杂交动物的特征是线粒体中电子传输系统的活性降低，线粒体是所有动物细胞的能量产生部分。为了扩大我们对杂交种线粒体功能障碍的理解，提出了两种新开发的分子工具：RNA干扰(用于操纵基因表达)和整个转录组测序(以获得基因表达的全局视图)。总而言之，这些将梳理出响应基因组杂交的基因表达变化与响应外部环境的变化。这些方法将用于比较自然种群和实验室杂交种群的反应，以确定与种群不亲和性有关的基因。尽管这项拟议的工作主要是由进化生物学中的问题推动的，但其对线粒体功能障碍的关注在整个生物医学科学中引起了广泛的兴趣，特别是在衰老和核移植领域。这些研究将为寻求整合分子生物学、生理学和遗传学研究以解决生物学中的重要问题的本科生、研究生和博士后研究人员提供独特的培训机会。这项工作的结果(以及所采用的方法)也是各种外展活动的起点，包括公开讲座、分子生态学课程开发，以及由一个环境教育组织在公立学校开展的K-12实验室活动。

Geographically isolated populations diverge genetically over time and may ultimately become new species. Early in the process, when the populations can still interbreed, genetic incompatibilities often result in loss of fitness in interpopulation hybrids. The proposed research uses the marine copepod, Tigriopus californicus, to examine molecular mechanisms underlying loss of fitness in hybrids. Recent work has shown that hybrids are characterized by reduced activity of the electron transport system in mitochondria, the energy producing part of all animal cells. Experiments are proposed to extend our understanding of mitochondrial dysfunction in hybrids using two recently developed molecular tools, RNA interference (to manipulate gene expression) and whole transcriptome sequencing (to obtain a global view of gene expression). Together, these will tease apart changes in gene expression in response to genome hybridization versus changes in response to the external environment. These methods will be used to compare the responses of natural populations and laboratory hybrids to determine the genes involved in population incompatibility. Although the proposed work is primarily motivated by questions in evolutionary biology, its focus on mitochondrial dysfunction is of broad interest throughout biomedical sciences, especially in the fields of aging and nuclear transplantation. The investigations will provide unique training opportunities for undergraduate, graduate and postdoctoral researchers seeking to integrate studies of molecular biology, physiology, and genetics to address important questions in biology. The results of the work (and the methods employed) also serve as starting points for diverse outreach activities including public lectures, curriculum development in molecular ecology, and development of K-12 laboratory activities implemented in public schools by an environmental education organization.