Characterizing Multigenerational Effects of Nicotine-Dependent Behaviors in Caenorhabditis Elegans

Abstract

This project aims to investigate the effects nicotine, a highly addictive chemical associated with tobacco smoking, have on offspring (F1 and F2) using the model organism Caenorhabditis elegans (C. elegans). C. elegans is a behavioral model representing an inveterate alternative especially useful in investigating multigenerational effects, where other models are costlier and more time-consuming. Our lab previously characterized nicotine-dependent behaviors of stimulation, withdrawal and adaption/tolerance. In this project, we further investigate the effects maternal nicotine exposure have on the offspring. We hypothesize that maternal exposure (F0) to nicotine has multigenerational influences such that the progeny has a higher tendency to develop nicotine-dependence. Several experiments were performed to test this hypothesis. First, the parent generation, F0, was dosed with either 308.8 M nicotine solution or K medium (control) from the L3 stage (larval stage 3) until early adulthood. The synchronized F1 and F2 grew to the adult stage without nicotine exposure. Then a behavior assay was conducted on the basis of locomotion either on nicotine containing or nicotine free plates. Increased smoothed speed (mm/s) on nicotine-free medium indicated the nicotine withdrawal response, the sensitive phenotype we previously characterized. Our data indicates that the F1 generation exhibits inherited neuromuscular paralysis and that the F2 generation exhibits withdrawal behaviors similar to that of the parent generation. Due to genetic conservation and behavioral analog between C. elegans and humans, our findings could elucidate multigenerational human addiction behaviors of nicotine-dependence.