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.
