Mechanism and Genetic Impacts of Transposon-Induced Duplications in Maize

研究目的：部分染色体重复（节段重复）是植物和动物基因组结构、功能和多样性的重要贡献者。 然而，关于复制是如何产生的，以及它们对基因表达和遗传重组的直接影响，我们知之甚少。 这个项目研究了转座因子或跳跃基因在产生片段复制中的潜在作用。本项目的目的是分离和鉴定一系列由Ac/Ds转座因子产生的玉米染色体部分重复。 复制体的结构将通过染色体的显微镜可视化来检查。 复制终点将被分离和研究，以精确地确定DNA复制和遗传重组如何参与形成复制。 最后，将详细分析部分染色体重复对遗传重组和基因表达的影响，因为这两个过程对于有效的植物育种至关重要。 该项目利用互补的分子，遗传和显微镜方法来研究这类重要的遗传变异。 更广泛的影响：该项目将提供重要的新见解转座因子在产生重复的作用，以及这些重复对遗传重组和基因表达的影响。 这些信息可能会导致作物育种的重大进展，从而提高农业效率和环境可持续性。 此外，该项目还将为当前和未来的科学家提供重要的培训机会，使他们掌握分子遗传学、经典遗传学、细胞遗传学和转座子生物学方面的各种途径和方法。三名研究生是研究项目的组成部分，将接受各种经典，细胞学和分子遗传学方法的培训。该项目还将提供实验室工作经验和在职培训，每年约6名本科生。此外，每年的细胞遗传学短期课程将培训12-18名高中学生和教师。这些培训活动将大大加强美国的科学基础设施。

Research Objectives: Partial chromosome duplications (segmental duplications) are important contributors to the structure, function and diversity of plant and animal genomes. However, very little is known concerning how duplications are generated, and their immediate effects on gene expression and genetic recombination. This project examines the potential role of transposable elements, or jumping genes, in generating segmental duplications. The aim of this project is to isolate and characterize a series of partial chromosome duplications in corn generated by Ac/Ds transposable elements. The structures of duplications will be examined by microscopic visualization of chromosomes. The duplication endpoints will be isolated and studied to determine precisely how DNA replication and genetic recombination are involved in forming duplications. Finally, the effects of partial chromosome duplications on genetic recombination and gene expression will be analyzed in detail, because these two processes are critical for effective plant breeding. This project utilizes complementary molecular, genetic and microscopic approaches to study this important class of genetic variants. Broader Impacts: This project will provide significant new insight into the role of transposable elements in generating duplications, and the impact these duplications have on genetic recombination and gene expression. This information may lead to significant advances in breeding of crop plants, thereby improving agricultural efficiency and environmental sustainability. In addition, this project will result in significant training opportunities for current and future scientists in a variety of approaches and methods in molecular genetics, classical genetics, cytogenetics and transposon biology. Three graduate students are integral to the research project and will be trained in a variety of classical, cytological, and molecular genetic approaches. The project will also provide laboratory work experience and on the job training for approximately six undergraduate students per year. In addition, an annual cytogenetics short course will train 12-18 high school students and teachers yearly. Together these training activities will significantly enhance the science infrastructure in the USA.