Collaborative Research: Patterns and Mechanisms of Gene Expression in Recent Allopolyploids of Recurrent Origin

合作研究：近期轮回异源多倍体的基因表达模式和机制

• 批准号: 0346591
• 负责人: Z. Jeffrey Chen
• 金额: $ 20.78万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-15 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0346591&HistoricalAwards=false
• 关键词: Collaborative; Research; Patterns; Mechanisms; Gene

Polyploidy (genome duplication) represents a major force in plant evolution and an important evolutionary process in other organisms, but the ecological, physiological, genetic, and genomic consequences of genome doubling remain mostly unknown. Most polyploids are formed via hybridization between two species, and it is unclear whether the polyploids express all of the attributes of both parents or are mosaics that combine some characters of each parent. Recent studies of polyploid gene expression have focused on artificially produced polyploids in Arabidopsis, cotton, and wheat rather than on naturally occurring polyploids. In addition, although most polyploid species have formed repeatedly in nature, nothing is known about the consequences of this recurrent formation on gene expression. A central question yet to be addressed is whether individuals of separate origin show similar or divergent gene expression profiles. A model system for the study of recent and recurrent polyploidy in natural populations is provided by Tragopogon (Asteraceae, the Sunflower family). Two new polyploid species (T. mirus and T. miscellus) were formed following the introduction of three diploid species (T. dubius, T. pratensis, and T. porrifolius) from Europe to western North America during the early 1900s. Tragopogon miscellus is particularly interesting because it has also formed reciprocally (that is, once with T. dubius as the maternal parent and multiple times with T. pratensis as the maternal parent). This project will involve molecular and genomic approaches to address a series of questions that are fundamental to an increased understanding of polyploidy. For example, does novel gene expression occur in these recently formed polyploids? Do gene expression patterns differ among polyploid populations of independent origin? Is gene expression affected by maternal and paternal contributions? Do gene expression patterns in F1 hybrids and newly produced polyploids differ from those of the naturally occurring polyploids? What types of genes undergo differential expression in the natural polyploids, and what types of mechanisms lead to the observed differences in gene expression? Such questions cannot be readily addressed in current crop systems or with resynthesized polyploids. This research will provide the first rigorous assessment of gene expression in natural polyploid populations, plus new insights into the rapid evolutionary success of two new polyploid species. The collaboration among PIs D. Soltis, P. Soltis, J. Tate (University of Florida) and Z. J. Chen (Texas A&M University) combines their respective expertise in evolutionary biology and molecular genetics. Opportunities for training of undergraduate and graduate students, post-docs, and K-12 teachers are integrated into the project.

多倍性（基因组复制）代表了植物进化的主要力量，也是其他生物的重要进化过程，但基因组加倍的生态、生理、遗传和基因组后果仍然是未知的。 大多数多倍体是通过两个物种之间的杂交形成的，目前还不清楚多倍体是否表达了双亲的所有属性，或者是联合收割机结合了双亲的一些特征。多倍体基因表达的最新研究集中在拟南芥、棉花和小麦中人工产生的多倍体，而不是自然产生的多倍体。此外，尽管大多数多倍体物种在自然界中重复形成，但对这种重复形成对基因表达的影响一无所知。 一个中心问题尚未得到解决的是不同来源的个体是否表现出相似或不同的基因表达谱。 Tragopogon（菊科，向日葵科）提供了一个研究自然居群中最近和复发多倍体的模式系统。 2个多倍体新种（T. mirus和T. miscellus）是在引入三个二倍体种（T. Albertus，T. pratensis和T. porrifolius）在20世纪初从欧洲到北美西部。 特别有趣的是，Tragopogon miscellus也曾与T. Alcohus作为母本，并多次与T. Pratensis作为母本）。 该项目将涉及分子和基因组方法来解决一系列问题，这些问题对于加深对多倍性的理解至关重要。 例如，新的基因表达是否发生在这些最近形成的多倍体中？ 基因表达模式在不同来源的多倍体群体中有差异吗？ 基因表达是否受母亲和父亲贡献的影响？ F1杂种和新产生的多倍体的基因表达模式与自然发生的多倍体不同吗？ 在天然多倍体中，哪些类型的基因经历了差异表达，哪些类型的机制导致了所观察到的基因表达差异？ 这些问题在目前的作物系统或再合成的多倍体中不能容易地解决。 这项研究将首次对自然多倍体种群中的基因表达进行严格评估，并对两种新多倍体物种的快速进化成功提供新的见解。 D.参与者之间的合作。Soltis，P. Soltis，J. Tate（佛罗里达大学）和Z. J. Chen（德克萨斯A M大学）结合了他们各自在进化生物学和分子遗传学方面的专业知识。 本科生和研究生，博士后和K-12教师的培训机会被纳入该项目。