Behavioral and Molecular Effects of 2,4-Dichlorophenoxyacetic Acid Exposure in Planarians

Author

• Emily Pintilie, Lynn University

Date of Award

5-12-2026

Document Type

Thesis

Granting Institution

Lynn University

Degree Name

Master of Science (M.S.)

Degree Program

Biological Sciences

Department

College of Arts and Sciences

First Advisor

Dr. Cassandra S. Korte

Second Advisor

Dr. Erika L. Doctor

Third Advisor

Dr. Félix Rivera-Mariani

Abstract

The widespread use of pesticides, such as 2,4-dichlorophenoxyacetic acid (2,4-D), raises serious concerns about their effects on non-target aquatic organisms. In vertebrates, 2,4-D has been associated with neurotoxic outcomes. Planarians offer a valuable system for toxicological studies because of their well-characterized nervous system, regenerative capacity, and measurable behavioral responses. This study investigated the neurotoxic effects of 2,4-D exposure in the planarian species Girardia dorotocephala, including the assessment of nociceptive behaviors, survival rate, phototactic responses, and DNA methylation. Worms were exposed to various concentrations of 2,4-D (0–100 mg/L) at multiple time points. Nociceptive responses, such as scrunching, C-shapes, and seizures, survival, and mortality, were monitored. Photophobic behavior was tested using wavelength-specific light stimuli to determine whether 2,4-D disrupted sensory-motor processing. DNA methylation ELISA assay was performed to determine whether 2,4-D causes epigenetic changes as a molecular proxy for 2,4-D exposure. Higher concentrations of 2,4-D induced abnormal nociceptive behaviors and increased mortality. However, phototaxis assays suggest that 2,4-D does not impair phototaxis in planarians. To our knowledge, this is the first study to demonstrate concentration-dependent DNA methylation changes in Girardia dorotocephala, providing an insight into the epigenetic effects of 2,4-D exposure. In our planarian model, our findings suggest that the environmental toxicant 2,4-D affects aquatic invertebrates at both behavioral and molecular levels, further supporting the use of planarians as a sensitive model for neurotoxicity and ecotoxicology research.

Recommended Citation

Pintilie, E. (2026). Behavioral and molecular effects of 2,4-Dichlorophenoxyacetic acid exposure in Planarians [Master's thesis, Lynn University]. SPIRAL. https://spiral.lynn.edu/etds/455