Meeting Abstract
Introduction: The herbicide Roundup and its active ingredient, Glyphosate, used for weed control, end up in water where they affects life, including, the brine shrimp Artemia franciscana, from the Great Salt Lake. The goals of this project were to understandthese herbicides a) short term effect, b) their long term effect and c) the shrimp stress response. Materials and Methods: In the short term exposure (a), Artemia larvae were exposed for 48 hours to Glyphosate and Roundup in concentration ranging from 10-2 to 10-7 and 0 (control, Co) g/l. In the long term exposure (b) larvae were raised in the above solutions in 0, 10-8, 10-7, 10-6, 10-5, 10-4 10-3g/l Glyphosate concentration. Survival, growth, maturation and fertility rates were recorded. For stress monitoring (c), the up-regulation of stress proteins hsp22, 70 and 90 was assessed. Results: a) All larvae and adult were killed by all Glyphosate solutions at 10-2 g/l concentration. Mortality rates at 10-3 g/l and below varied with the type of solution containing the Glyphosate. Shrimp placed in 10-4 g/l or lower concentrations survived as well as the control. b) Shrimp could not survive to maturation in Glyphosate/Roundup at 10-3 g/l or higher. Most shrimp matured in about 25 days after hatching, with no significant difference with the control. Fertility (or the number of eggs per brood) was the most affected. All shrimp exposed to any type of Glyphosate produced significantly less offspring than the control (60 or less in the exposed shrimp compared to 78 eggs/brood in the controls). In addition, an unusual number of aborted eggs was noticed. c- Heat-shock proteins 70 expression increased with higher Glyphosate exposure, suggesting upregulation. Conclusion: The most noticeable effect of Glyphosate is on fertility and potentially on embryonic development.
