Uncovering the Molecular Mechanisms of Selfish Genetic Elements

智力优势：有利基因通常在种群中持续存在并占据主导地位，而有害基因则消失。然而，一些非适应性基因已经找到了对抗自然选择的力量并渗透到种群中的方法；这些被称为自私遗传元素或自私基因。通过使用规避孟德尔遗传定律的遗传机制，这些元素能够增加频率并在种群中传播。一个引人入胜的例子是红粉甲虫的母性显性胚胎停滞(Medea)元素。杂合的美狄亚雌性将一种显性致死因子传递给孵化的幼崽，但在那些从父母中任何一方继承美狄亚等位基因的后代中，这种致死效应被关闭。因此，每个美狄亚等位基因既编码母体携带的“毒药”，也编码在胚胎中表达的“解毒剂”。关于这些元素是如何发挥作用的，人们知之甚少。因此，该项目旨在通过使用遗传和基因组工具来揭示参与自我选择的基因，以发现导致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和渗透到种群中的理解。这一知识可以提供一种新的机制，将特征转移到害虫种群中，使它们不那么有问题。该项目包括几个教育部分。该协会正在参加一项NSF综合研究生教育和研究培训(基因工程和社会：转基因害虫案例)，重点是培训学生掌握用于操纵害虫基因组的技术，以及评估这些遗传操作的特定产品的环境和社会文化适宜性所需的方法。这项研究将直接纳入IGERT课程和IGERT研究生研究员的研究。该项目还包括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的活动。此外，这项研究将通过PI和IGERT学生的外联活动广泛传播，以提高公众对转基因技术用途的认识。

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.