Trans-Generational Effect of Glyphosate-Based Herbicide (GBH) RoundupTM on Mitochondria Metabolism and Swimming Behavior in Zebrafish

Presentation Number: SAT 246
Date of Presentation: April 1st, 2017

Kingsley Ibhazehiebo*, Gaurav Kaushik and Deborah Marie Kurrasch
University of Calgary, Calgary, AB, Canada

Abstract

A causative relationship has been proposed linking environmental contaminant exposure to various cognitive and behavioral disorders. More recently, neurodevelopmental disorders such as autism, has also been linked to exposure to environmental toxicants, especially in utero. However, the molecular mechanisms responsible for transducing toxin exposure into disrupted neurodevelopment and altered behavior later in life remain relatively unexplored. Glyphosate -based herbicide such as RoundupTM, are the most extensively used agrochemical worldwide, and increasingly in urban and domestic environments. RoundupTM  exposure may be ubiquitous as it has been detected in the environment and in humans around the world. Although GBHs are marketed as non-toxic to humans or animals, emerging studies indicates otherwise as effect of GBHs on lower vertebrates and mammals world wide has been reported. Here, we studied the trans-generational effect of RoundupTM on developing zebrafish embryos, using mitochondria bioenergetics as a read-out for overall cellular health. We also explored the trans-generational consequences of restricted, early-life exposure to RoundupTM on behavior in zebrafish larvae later in life. Restricted exposure of embryonic zebrafish to low levels of RoundupTM during specific windows of development resulted in significantly increased basal respiration that was mitochondrially-mediated. Also, RoundupTM -exposed zebrafish larvae displayed hyperactive swimming behavior, suggesting long-lasting effects. In contrast, larvae born to zebrafish that were exposed to low level RoundupTM for restricted periods during development exhibited statistically decreased basal respiration that was also mitochondrially-mediated, in addition to showing decreased adenosine-tri-phosphate (ATP)-linked respiration. In addition, these larvae also displayed hypoactive swimming behavior and reduced total distance moved in a 20-minutes locomotor test, illustrating the importance of assessing trans-generational impact of RoundupTM exposure. Our study suggest that the consequences of RoundupTM exposure could be trans-generational, despite the metabolic effects differing in successive generations. Understanding the molecular consequences of environmental toxins on brain development during these initial, crucial stages may shed insight into the underlying etiology of a variety of neurological disorders.

 

Nothing to Disclose: KI, GK, DMK