Uncovering the Molecular Mechanisms of Selfish Genetic Elements

智力优势：优势基因通常在种群中持续存在并占主导地位，而有害基因则消失。然而，一些非适应性基因找到了对抗自然选择力量的方法，并渗透到种群中；这些被称为自私基因或自私基因。这些元素能够通过规避孟德尔遗传定律的遗传机制增加频率并在人群中传播。一个引人入胜的例子是红粉甲虫（Tribolium castaneum）中母体效应显性胚胎抑制（Medea）元素。杂合的美狄亚雌虫将一种显性致死因子传递给幼仔，但在那些从父母一方遗传了美狄亚等位基因的后代中，致死效应被关闭。因此，每个美狄亚等位基因都编码一种母体携带的“毒药”和一种在胚胎中表达的“解毒剂”。人们对这些元素的作用知之甚少。因此，本项目旨在利用遗传学和基因组学工具，揭示参与自我选择的基因，从而发现美狄亚自私行为的分子机制。更广泛的影响：这个项目将增加我们对自私基因如何逃避自然选择并渗透到种群中的理解。这一知识可以提供一种新的机制，将性状转移到害虫种群中，使它们的问题更少。该项目包括几个教育组成部分。PI正在参加NSF研究生教育与研究综合培训项目（基因工程与社会：转基因害虫案例），该项目侧重于培训学生掌握虫害基因组操作技术，以及评估这些基因操作特定产品的环境和社会文化适宜性所需的方法。这项研究将直接整合到IGERT的课程和研究生的研究中。该项目还包括一些活动，将为来自代表性不足群体的本科生提供参与尖端功能基因组研究的机会。此外，这项研究将通过PI和IGERT学生的外展活动广泛传播，以提高公众对转基因技术效用的认识。

Intellectual Merit: Advantageous genes normally persist and predominate in populations, while deleterious genes disappear. However, some non-adaptive genes have found ways to counter the forces of natural selection and infiltrate populations; these are known as selfish genetic elements or selfish genes. Such elements are able to increase in frequency and spread through populations by employing genetic mechanisms that circumvent Mendel's laws of inheritance. A fascinating case is that of the Maternal-Effect Dominant Embryonic Arrest (Medea) elements in the red flour beetle, Tribolium castaneum. Heterozygous Medea females transmit a dominant-lethal factor to hatchlings, but the lethal effect is shut down in those progeny that inherit a Medea allele from either parent. Thus, each Medea allele encodes both a maternally loaded "poison" and an "antidote" expressed in the embryo. Little is known about how such elements function. Therefore, this project is aimed at discovering the molecular mechanism responsible for Medea's selfish behavior by using genetic and genomic tools to uncover the genes involved in self-selection. Broader Impacts: This project will increase our understanding of how selfish genes escape natural selection and infiltrate populations. This knowledge could provide a new mechanism for transferring traits into pest populations to make them less problematic. The project includes several educational components. The PI is participating in an NSF Integrative Graduate Education and Research Traineeship (Genetic Engineering and Society: The case of transgenic pests) that is focused on training students in technologies used for manipulation of pest genomes as well as methods needed to assess the environmental and sociocultural appropriateness of specific products of these genetic manipulations. This research will be integrated directly into IGERT courses and research of IGERT graduate fellows. The project also includes activities that will provide undergraduates from underrepresented groups with an opportunity to participate in cutting-edge functional genomic research. Moreover, this research will be widely disseminated through outreach events by the PI and IGERT students to raise public awareness about the utility of transgenic technologies.