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Title:Molecular implications of prolonged DDT selection in Drosophila melanogaster
Author(s):Seong, Keon Mook
Director of Research:Pittendrigh, Barry
Doctoral Committee Chair(s):Pittendrigh, Barry
Doctoral Committee Member(s):Francis, Bettina; Paige, Ken; Hansen, Allison
Department / Program:Entomology
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Drosophila melanogaster
Insecticide resistance
Genome-wide evolution
Abstract:From the advent of the use of synthetic insecticide in the first half of the twentieth century, insecticide pressure has played a critical role in the evolution of insect populations. Genome-wide monitoring for the effect of such selection has not only provided considerable insight into an understanding of these evolutionary dynamics but also as a way to elucidate changes in individual genes or gene families. Although prior comparative genetic and genomics studies have revealed a large number of individual genes and gene families that may be selectively advantageous for insects over evolutionary time scales, most studies have been limited in that the researchers did not have access to populations within a known common origin for which a given evolutionary selection pressure has been well-defined or documented. In this study, I analyzed the genomes and transcriptomes of a highly DDT-resistant (91-R) Drosophila melanogaster and its corresponding DDT-susceptible (91-C) strain in order to characterize the impact of prolonged DDT selective pressure on genetic diversity for those strains. Comparing the transcriptomic response to DDT in 91-R and 91-C, I identified a multigenic adaptive response to DDT in 91-R along with multiple roles for gene regulatory cascades around stress responses, cell survival, and neurological function. Furthermore, both the genotypic and phenotypic diversity of the phase I detoxification gene, cytochrome P450, as well as phase III detoxification gene, ABC transporter, suggest an adaptive evolutionary response to multigenerational DDT selection pressure between 91-R and 91-C. Taken together, these findings offer evidence for the impact of widespread insecticide selection pressure on genomic diversity in Drosophila evolution along with insights across the entire genome into the functional implications of such positive selection pressure.
Issue Date:2017-04-20
Rights Information:Copyright 2017 Keon Mook Seong
Date Available in IDEALS:2017-08-10
Date Deposited:2017-05

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