Epigenetic and developmental effects from exposure to glyphosate and roundup on developing Medaka fish (Oryzias latipes)

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Chelsea M. Smith (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Ramji Bhandari

Abstract: RoundupĀ®, and other glyphosate-based herbicides, are the most commonly used herbicides in the world, yet their effects on developing fish embryos are not clearly understood. In the present study, medaka embryos were exposed to 0.5 mg/L glyphosate, 0.5 mg/L and 5 mg/L Roundup for 15 days, then allowed to mature. Embryos were examined at 4, 8, 15 and 100 dpf to determine if exposure to environmentally relevant concentrations of glyphosate and Roundup can induce developmental defects in fry after hatching and if exposure induces alterations in gene expression and global epigenetic effects, particularly DNA methylation, during early development resulting in alterations of reproductive success at adulthood. A significant decrease in cumulative hatching success for 0.5 mg/L Roundup and glyphosate exposure groups, and an increase in developmental abnormalities in medaka exposed to 0.5 mg/L glyphosate was observed. A significant downregulation of Dnmt1 and upregulation of Tet1, Tet2 and Tet3 were observed at 15 dpf, suggesting the role of demethylation in the observed phenotype. Furthermore, expression of Gpr54-1 was significantly downregulated in female brain samples exposed to 0.5 mg/L and 5 mg/L Roundup and in Gpr54-2 exposed to 0.5 mg/L Roundup. In testes samples, reproductive genes Fshr and Ara were significantly downregulated in medaka exposed to 0.5 mg/L Roundup and glyphosate, and in Dmrt1 and Dnmt1 exposed to 0.5 mg/L glyphosate. The study demonstrates that Roundup and its active ingredient glyphosate induce direct and long-term developmental, reproductive, and epigenetic effects due to exposure at environmentally relevant concentrations.

Additional Information

Language: English
Date: 2018
Epigenetic, Fish, Gene expression, Glyphosate, Medaka, Roundup
Oryzias latipes $x Development
Glyphosate $x Physiological effect

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