Yunhee JiFollow

Document Type



Doctor of Philosophy (PhD)


Public Health

First Advisor's Name

Marcus S. Cooke

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Stanislaw F. Wnuk

Second Advisor's Committee Title

committee member

Third Advisor's Name

Lidia Kos

Third Advisor's Committee Title

committee member

Fourth Advisor's Name

Quentin Felty

Fourth Advisor's Committee Title

committee member

Fifth Advisor's Name

Kim Tieu

Fifth Advisor's Committee Title

committee member

Sixth Advisor's Name

Helen Tempest

Sixth Advisor's Committee Title

committee member


DNA damage, Environmental exposure, Mitochondiral genomes, nuclear genomes, DNA repair

Date of Defense



All living organisms are continually exposed to various environmental stressors, be they anthropogenic or natural in origin. Many stressors share a common toxic mechanism, generating highly reactive chemical species that can have detrimental effects. A proportion of these chemical species evade the cell’s defenses and damage cellular components, including DNA. Measurement of global genome levels of DNA and cellular damage has implicated environmental stressors in major human health issues (e.g., cancer, aging, cardiovascular, and neurodegenerative diseases). Current associations between DNA damage and disease are based upon crude assessments of global genome damage, which provide limited mechanistic information on how damage leads to disease. Furthermore, DNA damage is not uniformly distributed across the genome; accumulation, or persistence, of damage in regions of the genome vital to the functioning of the cell, will have downstream consequences. Thus, we proposed, that the role of DNA damage in disease can only be understood by examination of damage in the context of its location and damage response during the repair. Currently we lack information concerning how the cell maintains baseline levels of DNA damage and its spatio-temporal distribution across the genome. This is fundamental to our understanding of how the cell responds to damage and whether regions are targeted for prioritized repair. In this study, we have refined a popular method of assessing global DNA damage, to increase the efficiency of the assay, mapped UV-induced T<>T across both nuclear and mitochondrial genomes, and evaluated the changes in the cellular DNA damage response during bacterial infection. The aim of these studies was to evaluate the importance of cellular response to exposure to environmental toxicants.




Previously Published In

Karbaschi, M., Ji, Y., Abdulwahed, A. M. S., Alohaly, A., Bedoya, J. F., Burke, S. L., ... & Cooke, M. S. (2019). Evaluation of the Major Steps in the Conventional Protocol for the Alkaline Comet Assay. International Journal of Molecular Sciences, 20(23), 6072.

Alhegaili, A. S., Ji, Y., Sylvius, N., Blades, M. J., Karbaschi, M., Tempest, H. G, ... & Cooke, M. S. (2019). Genome-Wide Adductomics Analysis Reveals Heterogeneity in the Induction and Loss of Cyclobutane Thymine Dimers across Both the Nuclear and Mitochondrial Genomes. International journal of molecular sciences, 20(20), 5112.

Ji, Y., Karbaschi, M., & Cooke, M. S. (2019). Mycoplasma infection of cultured cells induces oxidative stress and attenuates cellular base excision repair activity. Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 845, 403054.

Included in

Public Health Commons



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