Variation in Toxicity of a Current-use Insecticide Among Resurrected Daphnia Pulicaria Genotypes
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Toxicology
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This study examined how genotypes of Daphnia pulicaria from a single population, separated by thousands of generations of evolution in the wild, differ in their sensitivity to a novel anthropogenic stressor. These genotypes were resurrected from preserved resting eggs isolated from sediments belonging to three time periods: 2002-2008, 1967-1977, and 1301-1646 A.D. Toxicity of the organophosphate insecticide chlorpyrifos was determined through a series of acute toxicity tests. There was a significant dose-response effect in all genotypes studied. Moreover, significant variation in toxicity among genotypes within each time period was detected. Importantly, a significant effect of time period on sensitivity to chlorpyrifos was found. Analysis of the median effect concentrations (EC50s) for genotypes within each time period indicated that the 1301-1646 genotypes were 2.7 times more sensitive than the 1967-1977 genotypes. This trend may be partially explained by microevolutionary shifts in response to cultural eutrophication.
Yousey A, Roy Chowdhury P, Biddinger N, Shaw J, Jeyasingh P, Weider L R Soc Open Sci. 2018; 5(3):172193.
PMID: 29657812 PMC: 5882736. DOI: 10.1098/rsos.172193.
Daphnia magna transcriptome by RNA-Seq across 12 environmental stressors.
Orsini L, Gilbert D, Podicheti R, Jansen M, Brown J, Shams Solari O Sci Data. 2016; 3:160030.
PMID: 27164179 PMC: 4862326. DOI: 10.1038/sdata.2016.30.