Honors Program Theses


Open Access Honors Program Thesis

First Advisor

Kavita Dhanwada


Atrazine is one of the most abundantly used herbicides in the United States. It works by inhibiting photosynthesis in broad leaf and grassy weeds. Consequently, with its frequent use, atrazine can contaminate many drinking water sources due to run-off from treated fields. While many studies have shown detrimental effects occur in various model organisms using very high levels of atrazine, not much is known about what effects occur due to lower levels of atrazine exposure. The current research project analyzed the effects of atrazine on human liver cells (HepG2). Specifically, we focused on the proteins that regulate cell cycle progression through the Gap 1 phase, D 1 and E cyclin. A critical threshold level of these cyclins must be reached before the cell can proceed into S phase of the cell cycle. Timecourse experiments were performed to determine if the expression of D 1 and E cyclins was altered in the presence of atrazine. For the timecourse, HepG2 cells were treated with either 300 ppb or 500 ppb concentrations of atrazine and compared to cells that have not been exposed to the herbicide (0 ppb ). Nuclear proteins were isolated at particular times after exposure with herbicide (0, 4, 8, 12, 24, and 48 hours). The nuclear proteins were quantified and analyzed by Western Blot analysis to compare the expression of cyclins from control vs. untreated cells. Data suggests that the expression of D 1 cyclin is not altered in atrazine treated cells compared to control samples, while cyclin E expression is decreased in atrazine treated cells compared to control samples.

Year of Submission



Department of Biology

University Honors Designation

A thesis submitted in partial fulfillment of the requirements for the designation University Honors


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Date Original


Object Description

1 PDF file (v, 26 pages)