The B chromosome of maize: Drive and Genomic Conflict

玉米 B 染色体：驱动力和基因组冲突

• 批准号: 2214243
• 负责人: James Birchler
• 金额: $ 122.83万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2214243&HistoricalAwards=false
• 关键词: chromosome; maize; Drive; Genomic; Conflict

Varieties of corn have an extra chromosome that is not essential called the B chromosome. This chromosome has properties that, based on analysis of its DNA sequence, have allowed it to persist from one generation to the next for millions of years, despite the fact that it is not needed for the plant. While these properties are beneficial to the success of the B chromosome, they often have negative consequences for the normal corn chromosomes such as chromosome fracture and the activation of transposable elements that have the potential to jump around the genome and cause mutations. A genetic and molecular analysis will be conducted to learn the nature of these B chromosome properties and how the corn genome has been impacted by the presence of the B chromosome. The B chromosome appears to have been involved in restructuring the corn chromosomes, so an understanding of these properties will help provide insight into the nature of, and variation in the maize genome. The research will involve participants at all educational levels and will involve training in genetics, genomics, and computational biology. The supernumerary B chromosome of maize is a novel, selfish genetic system involving a whole chromosome that impacts genomic processes in general. The B chromosome has manipulated cellular processes to ensure proper segregation in male meiosis by increasing recombination in heterochromatin, by using a novel meiotic process to stabilize itself in meiosis, by delaying replication of the centromere at the one mitosis that makes the two sperm, and by mediating fertilization of the egg by B containing sperm. Experiments will examine the mechanism of centromere nondisjunction, the identity and function of the trans-acting factors needed for nondisjunction, the nature of the univalent stabilization process, the nature of the modulation of recombination across the genome, and aspects of genomic conflict such as de-silencing of transposable elements, identifying the gene responsible for genomic shattering by B chromosomes in some backgrounds, and the gene responsible for variation in preferential fertilization. The completion of this project will provide data that support a new paradigm in the understanding of a suite of co-opted functions by a mega selfish genetic entity. The interdisciplinary team will seek to understand this selfish entity to gain new insight into concepts previously unexplored in any system about genetic drive and genomic conflict. A training program across biological disciplines with computational analyses will be conducted at all educational levels.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

玉米的品种具有额外的染色体，这不是必不可少的称为B染色体。该染色体具有基于对DNA序列的分析的特性，尽管该植物不需要它，但它仍可以在数百万年内持续数百万年。尽管这些特性对B染色体的成功是有益的，但它们通常对正常玉米染色体（例如染色体骨折）和可转座元件的激活产生负面影响，这些元素的激活有可能在基因组上跳跃并引起突变。将进行遗传和分子分析，以了解这些B染色体特性的性质，以及B染色体的存在如何影响玉米基因组。 B染色体似乎参与了重组玉米染色体，因此对这些特性的理解将有助于洞悉玉米基因组的性质和变化。该研究将涉及所有教育水平的参与者，并涉及遗传学，基因组学和计算生物学的培训。玉米的超级B染色体是一种新型的自私遗传系统，涉及整个染色体，总体上影响基因组过程。 B染色体通过使用一种新型的减数分裂过程来稳定自身，通过增加一种有丝分裂的复制，通过使两种精子的复制延迟了两种精子，并通过含有bigermity iggers iggers igemiatians，B染色体已操纵细胞过程，通过增加异染色质的重组来确保男性减数分裂的适当分离。实验将检查中心粒非分离的机制，非分离所需的跨性因素的身份和功能基因负责优先受精的变异。该项目的完成将提供支持新范式的数据，以理解巨型自私遗传实体的一系列选手功能。跨学科团队将寻求理解这个自私的实体，以获得对以前在任何系统中有关遗传驱动和基因组冲突的概念的新见解。将在所有教育层面上进行跨生物学学科的培训计划。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响审查标准通过评估来支持的。