(+) Anatoxin-a elicits differential survival, photolocomotor behavior, and gene expression in two alternative vertebrate models

Abstract

Anatoxin-a is a globally occurring, yet understudied, chiral cyanobacterial toxin that threatens public health and the environment. It has led to numerous dog. livestock and bird poisonings and although it has been studied in rodent models, comparatively little research has occurred in aquatic species. To advance a comparative toxicology understanding of this toxin in alternative vertebrate models, developing zebrafish and fathead minnow were exposed to environmentally relevant and elevated levels (13–4400 μg/L) of (+) anatoxin-a to examine potential mortality and sublethal effects, including photolocomotor behavior and gene expression responses. We observed significantly higher mortality (p 0.05) transcriptional changes were observed in the fathead minnow model. These differential responses between commonly employed species employed as alternative vertebrate models in toxicology research and chemicals risk assessments highlight the need for more comparative studies to understand sensitivities and variations in organismal response. Furthermore, we identified higher mortality, refractory behavioral effects, and gene expression in (+) anatoxin-a exposed fish when compared to previously reported (±) anatoxin-a (racemic 50:50 enantiomer mixture) studies, which is frequently used as a surrogate chemical for experimental work. Our findings identify the importance of understanding species and enantiomer specific effects of natural toxins.

Keywords

• Behavior
• Water Quality
• Natural Toxin
• Neurotransmission
• Chiral Toxicology