Transcriptomic, biochemical and individual markers in transplanted Daphnia magna to characterize impacts in the field

Abstract

Daphnia magna individuals were transplanted across 12 sites from three Spanish river basins (Llobregat, Ebro, Jucar) showing different sources of pollution. Gene transcription, feeding and biochemical responses in the field were assessed and compared with those obtained in re-constituted water treatments spiked with organic eluates obtained from water samples collected at the same locations and sampling periods. Up to 166 trace contaminants were detected in water and classified by their mode of action into 45 groups that included metals, pharmaceuticals, pesticides, illicit drugs, and other industrial compounds. Physicochemical water parameters differentiated the three river basins with Llobregat having the highest levels of conductivity, metals and pharmaceuticals, followed by Ebro, whereas the Jucar river had the greatest levels of illicit drugs. D. magna grazing rates and cholinesterase activity responded similarly than the diversity of riparian benthic communities. Transcription patterns of 13 different genes encoding for general stress, metabolism and energy processes, molting and xenobiotic transporters corroborate phenotypic responses differentiated sites within and across river basins. Principal Component Analysis and Partial Least Square Projections to Latent Structures regression analyses indicated that measured in situ responses of most genes and biomarkers and that of benthic macroinvertebrate diversity indexes were affected by distinct environmental factors. Conductivity, suspended solids and fungicides were negatively related with the diversity of macroinvertebrates cholinesterase, and feeding responses. Gene transcripts of heat shock protein and metallothionein were positively related with 11 classes of organic contaminants and 6 metals. Gene transcripts related with signaling paths of molting and reproduction, sugar, protein and xenobiotic metabolism responded similarly in field and lab exposures and were related with high residue concentrations of analgesics, diuretics, psychiatric drugs, β blockers, illicit drugs, trizoles, bisphenol A, caffeine and pesticides. These results indicate that application of omic technologies in the field is a promising subject in water management.

Transgenerational Effects of Environmentally Relevant Concentrations of Atrazine and Glyphosate Herbicides, Isolated and in Mixture, to Freshwater Microcrustacean Daphnia Magna

“…The in uence on the enzymatic activities of CAT and GST in D. magna has been related to the presence of contaminants from the pesticide class, with the values determined for these enzymes slightly varying when compared to data reported in several studies (Rivetti et al, 2015). This fact may be linked to several factors that can cause variability in these parameters, such as the algae species used in feeding, the age and litter of organisms, and also experimental conditions such as temperature and photoperiod (Moreira et al, 2020).…”

Nutrients, emerging pollutants and pesticides in a tropical urban reservoir: Spatial distributions and risk assessment

“…The evaluation of the presence and concentrations of the EPs and pesticides in the Guarapiranga reservoir, with assessment of the potential risks, constitutes a first step in understanding the impacts of these pollutants in the reservoir. Further research concerning the real effects on the ecosystem should include community analysis, the use of biomarkers (understood as any measurable molecular, cellular, histological, physiological, or behavioral response; Depledge, 1994), in situ bioassays, and bioassays with other test organisms (Faria et al, 2010a, b;Rivetti et al, 2015).…”

Acute hydrogen peroxide (H2O2) exposure does not cause oxidative stress in late-copepodite stage ofCalanus finmarchicus

“…Importantly however, most studies on antioxidants in microcrustaceans have involved gene expression analyses alone and not being complemented with enzyme activity measurements, but there are exceptions, e.g. in the study on Daphnia magna transplanted to polluted areas (Rivetti et al, 2015). No significant differences between treatments were observed for SOD and CAT, however, a weak negative relationship (p=0.548, R2=0.39, linear regression, slope= -1.6) between their activities in the samples was observed.…”