Abstract

Aedes aegypti mosquitoes, vectors for many human diseases, begin life as larvae developing in water, potentially exposed to runoff with herbicides and pesticides. This study serves as a novel investigation into the transstadial effects of exposure to Roundup on A. aegypti life history, immunity, and stress response and aims to account for these effects in an R0 model for vectorborne disease transmission. Prior work has shown that Roundup negatively affects mosquito life history. I hypothesized that larval exposure to the maximum sublethal dose of Roundup (7189µg/L) would negatively impact A. aegypti life history, immunity (candidate gene approach), and stress response (heat shock protein expression and fluctuating asymmetry). No significant differences were found for survival from the larval to adult stages, body size, size or shape fluctuating asymmetry, or sex ratio. However, the Roundup treatment group developed significantly slower for both time to pupation and to adult eclosion (both p < 0.0001). Adult immune gene expression showed no difference between groups, but the larval immune genes Dome (JAK-STAT pathway) and Spatzle (TOLL pathway) were downregulated in the Roundup treatment (p=0.0383 and p=0.0035, respectively), suggesting the larvae have reduced immunity. This study suggests that Roundup may have off-target effects on A. aegypti mosquitoes that are unaccounted for by current models, and these effects may potentially alter disease transmission to human hosts.

Thesis Completion

2020

Semester

Spring

Thesis Chair

Fedorka, Kenneth

Co-Chair

Teter, Kenneth

Degree

Bachelor of Science (B.S.)

College

College of Medicine

Department

Burnett School of Biomedical Sciences

Degree Program

Biomedical Sciences

Language

English

Access Status

Open Access

Release Date

5-1-2020

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