CAREER: Functional and evolutionary analysis of de novo evolved genes in Drosophila male reproduction

所有物种都与其他生物有许多共同的基因，但每个物种都有一些新基因，这些基因是最近才形成的，因此要么是该物种独有的，要么是与它最亲近的物种共有的。在许多动物和植物物种中，许多这样的新进化基因被认为会影响男性生殖系统。该项目的目标是通过关注果蝇模型系统中影响精子功能的基因来确定新进化的基因是如何影响雄性生殖成功的。这项研究将产生关于新基因如何改变生殖系统以使其携带者受益的重要基础科学知识。其更广泛的意义在于，有可能开发出抑制农业害虫或传播人类疾病的昆虫物种（如携带疟疾和寨卡病毒的蚊子）繁殖的策略。通过确定谱系特异性基因对雄性生殖的重要性，这项研究可能有助于开发智能杀虫剂，或者针对仅存在于问题昆虫物种而不存在于周围环境中其他有益昆虫的基因的遗传操作策略。该项目还将通过增加本科生参与原创研究和支持创新的指导计划来造福社会，这些计划鼓励来自STEM学科中代表性不足的群体的学生坚持不懈。这项研究将在一个专门的本科生机构进行，部分将由中级遗传学课程的学生和在教师实验室进行独立研究的学生进行。该项目还将支持一项计划，让来自代表性不足群体的一年级大学生在入学后立即加入研究实验室，为这些学生提供一种社区意识，并在他们进入大学时向他们介绍科学研究。最后，该项目将支持一个由学生管理的组织，该组织将大学生与来自服务不足的公立高中的女孩配对，每周进行辅导会议，包括数学和科学技能方面的帮助。该项目特别关注所谓的“新生”基因，即最近从非编码DNA序列进化而来的基因。以前对各种分类群的研究主要集中在识别这些基因并研究它们在种群中的出现，但对它们特定的分子和细胞功能知之甚少。在安全且基因易于处理的果蝇模型系统中，该项目将首先使用RNA干扰技术筛选睾丸中表达的所有新生基因，以研究对男性生育能力的影响。完全生育所需表达的基因将成为功能表征的目标，这将通过标记转基因、抗体和CRISPR/ cas9介导的敲除突变系的发展而促进。这些工具将用于细胞学实验，以研究每个基因如何影响精子发生过程和/或成熟精子转移到雌性后的功能。在进行这些功能基因分析的同时，还将研究相关果蝇物种中每个基因的进化史，以了解基因是如何从非编码DNA序列中产生的，以及它编码的蛋白质自出现以来是如何进化的。对于显示出物种间快速分化特征的新生基因，将进行进一步的基因实验，以确定分化的功能后果。综上所述，这些实验将为新基因创造过程如何改变生殖表型提供一个全面的视角。

All species share many genes in common with other organisms, but each species has a handful of new genes that came into existence only recently and are thus either unique to that species or shared only with its closest relatives. In a variety of animal and plant species, many such newly evolved genes are thought to impact the male reproductive system. The goal of this project is to determine how newly evolved genes influence male reproductive success by focusing on those that affect sperm function in the fruit fly model system, Drosophila melanogaster. This research will generate important basic science knowledge about how new genes change reproductive systems to the benefit of their carriers. Its broader implications relate to the potential development of strategies that inhibit the reproduction of insect species that are agricultural pests or that transmit human diseases, such as the mosquitoes that carry malaria and the Zika virus. By establishing the importance of lineage-specific genes for male reproduction, this research may aid in the development of smart pesticides, or genetic manipulation strategies that target genes found only in the problematic insect species and not other beneficial insects in the surrounding environment. This project will also benefit society by increasing the participation of undergraduates in original research and supporting innovative mentoring programs that encourage the persistence of students from groups that are underrepresented in STEM disciplines. The research will be conducted at an exclusively undergraduate institution and will be carried out, in part, by students in an intermediate-level Genetics course and students conducting independent research in a faculty member's lab. The project will also support a program in which first-year college students from underrepresented groups join research labs immediately upon their arrival on campus, providing these students with a sense of community and introducing them to scientific research as they begin college. Finally, the project will support a student-run organization that pairs college students with girls from underserved public high schools for weekly mentoring sessions that include assistance with math and science skills.This project focuses specifically on so-called "de novo" genes that have recently evolved from non-coding DNA sequence. Previous research from a variety of taxa has focused on identifying these genes and studying their emergence within populations, but little is known about their specific molecular and cellular functions. Working in the safe and genetically tractable Drosophila melanogaster model system, this project will begin by using RNA interference to screen all de novo genes expressed in the testes for effects on male fertility. Genes whose expression is required for full fertility will become targets for functional characterization, which will be facilitated by the development of tagged transgenes, antibodies, and CRISPR/Cas9-mediated knockout mutant lines. These tools will be used in cytological experiments to investigate how each gene influences the process of spermatogenesis and/or the function of mature sperm after they are transferred to females. In parallel with these functional genetic analyses, the evolutionary history of each gene will be examined across related Drosophila species in order to understand how the gene arose from non-coding DNA sequence and how the protein it encodes has evolved since its emergence. For de novo genes that show signatures of rapid divergence between species, further genetic experiments will be conducted to determine the functional consequences of divergence. Taken together, these experiments will provide a comprehensive view of how the process of new gene creation can modify reproductive phenotypes.