Investigating the Impact of Chronic Atrazine Exposure on Sexual Development in Zebrafish

Autor: Robert L. Tanguay, David C. Volz, Margaret M. Corvi, Kerri Stanley, Tracy S. Peterson, Michael L. Kent, Alan J. Hosmer, Jane K. La Du, Stephen W. Feist
Rok vydání: 2012
Předmět:
Zdroj: Birth Defects Research Part B: Developmental and Reproductive Toxicology. 95:276-288
ISSN: 1542-9733
DOI: 10.1002/bdrb.21016
Popis: Atrazine (ATZ) is a selective triazine herbicide used primarily for pre-emergent weed control in corn, sorghum and sugar cane production. It is one of the most widely used herbicides in North America. Some research published over the last decade suggests that chronic exposure to environmentally relevant ATZ concentrations can adversely impact gonadal development and/or sexual differentiation in amphibians and fish, while other studies report no effect, or moderate effects. As a result, contrasting conclusions have been published regarding the potential effects of the herbicide ATZ on aquatic species. Two near-identical four-month studies in 2009 (Study I) and 2010 (Study II), were performed investigating the potential for chronic ATZ exposure to affect zebrafish (Danio rerio) sexual development and differentiation. Zebrafish, were chronically exposed to 0, 0.1, 1, 10 µM ATZ or 1 nM 17α-estradiol (E2). Fish were histologically examined to assign gender and to evaluate potential impacts of E2 or ATZ on gonadal development. Exposure to E2 consistently resulted in a significantly higher proportion of female fish to normal male fish when compared to unexposed fish (both studies). In both studies, ATZ exposure did not significantly influence the percentage of female or male fish when compared to unexposed fish. A greater percentage of abnormally developed male fish and fish lacking differentiated gonadal tissue was observed in Study II E2 exposures but not in ATZ exposures. Together, these studies indicate that long-term exposure to ATZ at or above environmentally relevant concentrations does not significantly impact zebrafish gonadal development or sexual differentiation.
Databáze: OpenAIRE