Polymorphic Duplications in the Evolution of New Genes in Drosophila

智力优势：基因复制是一种产生新基因的机制，是与表型变异相关的新功能进化的重要遗传新颖性。基因复制是如何在一个物种种群中随着时间的推移而产生和大量变化的尚不清楚。这项研究旨在了解导致种群中某些个体产生新基因功能的遗传机制和进化力量。本研究以果蝇为模型，采用综合方法在种群水平上解决与新基因功能进化相关的关键问题。首先，为了确定串联重复和分散重复的频率，将使用荧光标记和其他技术，对数百个已知存在于中高频率的多态性基因重复进行染色体位置和序列分析。其次，为了测试与基因复制功能相关的进化约束的重要性，将检查和比较新基因复制的序列变异和表达模式在功能和非功能位点之间的差异。第三，将通过比较物种内和物种间的变异来研究控制生存和自然选择的进化力量的影响。总之，这些实验的结果将为新基因功能的进化提供重要的见解。更广泛的影响：该项目将生成一个大型的具有良好特征的多态副本数据集，并将向公众开放。该项目将与学生和公众的教育密切相关，并将促进芝加哥大学附近社区中代表性不足的族裔群体的教育。该项目将与芝加哥州立大学（CSU）合作，为CSU生物学专业的学生开辟分子进化教学和科研培训的新方向，包括参加暑期研究，参加基因组进化的本科课程，以及参与相关的教育活动。此外，该项目将培养研究生和博士后，从而有助于他们作为独立科学家的职业发展。

Intellectual Merit: Gene duplication is a mechanism to generate new genes, an important genetic novelty for evolution of new functions associated with phenotypic variation. How a gene duplicate arises and changes in abundance over time in a species population is unclear. This research aims to understand the genetic mechanisms and evolutionary forces that lead to new gene functions in some individuals in a population and not in others. Using fruit flies as a model, this study applies an integrated approach to address key questions related to the evolution of new gene functions on a population level. First, to determine the frequency of tandem versus dispersed duplications, hundreds of polymorphic gene duplicates, known to be present at intermediate or high frequencies, will assayed for their chromosomal locations and sequences, using florescence labeling and other techniques. Second, to test the importance of evolutionary constraints related to functionality of the gene duplicates, sequence variation and expression patterns of the new gene duplicates will be examined and compared among functional and non-functional sites. Third, the influence of evolutionary forces governing survival and natural selection will be investigated by comparing within- and between-species variation. Together, the results of these experiments will provide important insights into the evolution of new gene functions.Broader Impacts: This project will generate a large well-characterized dataset of polymorphic duplicates that will be made publicly available. This project will be closely tied to the education of students and the public and will promote education of under-represented ethnic groups in the communities neighboring the University of Chicago. In collaboration with Chicago State University (CSU), this project will initiate a new direction of teaching and research training in molecular evolution for CSU biology students, including opportunities to participate in summer research, to take undergraduate courses about genome evolution, and to engage in related educational activities. In addition, this project will train graduate students and postdoctoral students, thus contributing to their career development as independent scientists.