A multivariate biomarker‐based model predicting population‐level responses of Daphnia magna

Abstract

A multivariate model is proposed relating short-term biomarker measurements in Daphnia magna to chronic effects (21-d exposure) occurring at the population level (time to death, mean brood size, mean total young per female, intrinsic rate of natural increase, net reproductive rate, and growth). The results of the short-term exposure (48 h-96 h) to eight model toxicants (cadmium, chromium, mercury, tributyl tin, linear alkylsulfonic acid, sodium pentachlorophenolate, lindane, and 2,4-dichlorophenoxyacetic acid) on the following biomarkers were used for the multivariate model: digestive enzymes (amylase, cellulase, beta-galactosidase, trypsin, and esterase), enzymes of the intermediary metabolism (glycogen phosphorylase, glucose-6-phosphate dehydrogenase, pyruvate kinase, lactate dehydrogenase, and isocitrate dehydrogenase), cellular energy allocation (CEA) (protein, carbohydrate, and lipid content and electron transport activity), and DNA damage and antioxidative stress activity. Using partial least squares to latent structures (PLS), a two-component model was obtained with R2 of 0.68 and a Q2 value of 0.60 based on the combined analysis of a limited number of the 48- and 96-h biomarker responses. For the individual population-level responses, the R2 values varied from 0.66 to 0.77 and the Q2 values from 0.52 to 0.69. Energy-related biomarkers (cellular energy allocation, lipid contents, anaerobic metabolic activity--pyruvate kinase, and lactate dehydrogenase), combined with parameters related to oxidative stress (catalase) and DNA damage measured after 48 and 96 h of exposure, were able to predict long-term effects at higher levels of biological organization.

Effects of acclimation temperature and cadmium exposure on cellular energy budgets in the marine molluskCrassostrea virginica: linking cellular and mitochondrial responses

“…The disconnection between indices of energy supply and demand also has important methodological implications, suggesting that demand-side and supply-side endpoints should be considered separately in studies of energy budgets. It strongly cautions against the use of capacity indices such as the maximum activity of electron transfer system as a measure of energy demand, as was proposed recently (Fanslow et al, 2001;De Coen and Janssen, 2003;Smolders et al, 2004). Our study shows that both elevated temperatures and Cd exposure lead to high energy demand and adversely affect mitochondrial aerobic capacity despite different molecular mechanisms of action.…”

Assessment of the effect of a commercial formulation of Methomyl on reproduction of Daphnia obtusa Kürz (1874)

“…These results could be due to the toxicity of pesticide that inhibits the endocrine effect. On the other hand, survival and growth depend on energy availability, and pesticides are known to reduce cellular energy budgets in daphnids (De Coen & Janssen, 2003;Barata et al, 2004). Pereira et al (2010) reported that Methomyl promoted differential transcription of energy-related genes in Daphnia magna.…”

Energy reserves and accumulation of metals in the ground beetle Pterostichus oblongopunctatus from two metal-polluted gradients

“…The majority of studies on energy budgets have been performed with aquatic organisms (De Coen and Janssen 1997; 2003a; 2003b; Verslycke et al 2004a; Erk et al 2008; Smolders et al 2003). Reduced energy reserves were reported in a study of protein, glycogen, and lipid contents in isopods from terrestrial ecosystems (Donker 1992).…”