Developmental origins of neurotransmitter and transcriptome alterations in adult female zebrafish exposed to atrazine during embryogenesis. (3rd July 2015)

• Record Type: Journal Article
• Authors: Wirbisky, Sara E.; Weber, Gregory J.; Sepúlveda, Maria S.; Xiao, Changhe; Cannon, Jason R.; Freeman, Jennifer L.
• Is Part Of: Toxicology. Volume 333(2015)
• Page Start: 156
• Page End: 167
• Publication Date: 2015-07-03
• Subjects: Atrazine -- Development -- Developmental origins of health and disease -- Neurotransmitters -- Transcriptomics -- Zebrafish; Toxicology -- Periodicals; Chemicals -- Physiological effect -- Periodicals; 615.9005
• DOI: 10.1016/j.tox.2015.04.016
• Languages: English
• ISSNs: 0300-483X

Abstract

Highlights: Embryonic atrazine exposure does not alter neurotransmitter levels in larvae. Adult neurotransmitter alterations were female and serotonergic pathway specific. Genes associated with serotonergic pathway were altered in transcriptomic analysis. Findings support developmental origin of neurological alterations in adult females. Abstract: Atrazine is an herbicide applied to agricultural crops and is indicated to be an endocrine disruptor. Atrazine is frequently found to contaminate potable water supplies above the maximum contaminant level of 3 μg/L as defined by the U.S. Environmental Protection Agency. The developmental origin of adult disease hypothesis suggests that toxicant exposure during development can increase the risk of certain diseases during adulthood. However, the molecular mechanisms underlying disease progression are still unknown. In this study, zebrafish embryos were exposed to 0, 0.3, 3, or 30 μg/L atrazine throughout embryogenesis. Larvae were then allowed to mature under normal laboratory conditions with no further chemical treatment until 7 days post fertilization (dpf) or adulthood and neurotransmitter analysis completed. No significant alterations in neurotransmitter levels was observed at 7 dpf or in adult males, but a significant decrease in 5-hydroxyindoleacetic acid (5-HIAA) and serotonin turnover was seen in adult female brain tissue. Transcriptomic analysis was completed on adult female brain tissue to identify molecular pathways underlying the observed neurological alterations. Altered expression of 1928, 89, and 435 genes in the females exposed to 0.3, 3, or 30 μg/L atrazine during embryogenesis were identified, respectively. There was a high level of overlap between the biological processes and molecular pathways in which the altered genes were associated. Moreover, a subset of genes was down regulated throughout the serotonergic pathway. These results provide support of the developmental origins of neurological alterations observed in adult female zebrafish exposed to atrazine during embryogenesis.