Systems biology meets stress ecology: linking molecular and organismal stress responses in Daphnia magna

Abstract

Background: Ibuprofen and other nonsteroidal anti-inflammatory drugs have been designed to interrupt eicosanoid metabolism in mammals, but little is known of how they affect nontarget organisms. Here we report a systems biology study that simultaneously describes the transcriptomic and phenotypic stress responses of the model crustacean Daphnia magna after exposure to ibuprofen. Results: Our findings reveal intriguing similarities in the mode of action of ibuprofen between vertebrates and invertebrates, and they suggest that ibuprofen has a targeted impact on reproduction at the molecular, organismal, and population level in daphnids. Microarray expression and temporal real-time quantitative PCR profiles of key genes suggest early ibuprofen interruption of crustacean eicosanoid metabolism, which appears to disrupt signal transduction affecting juvenile hormone metabolism and oogenesis.

Reproductive regulators in decapod crustaceans: an overview

“…Further, they also found in D. magna that somatic growth is primarily constrained by the availability of sterols, and reproduction is primarily constrained by the availability of EPA. Current evidence suggests that the main mode of action of the nonsteroidal anti-inflammatory drug ibuprofen in D. magna relates to interruption of eicosanoid biosynthesis, which reduces fecundity (Heckmann et al, 2008), where both prostanoids and lipoxygenase products appear to be important agents in oogenesis and embryogenesis (Medeiros et al, 2004).…”

“…Further, they also found in D. magna that somatic growth is primarily constrained by the availability of sterols, and reproduction is primarily constrained by the availability of EPA. Current evidence suggests that the main mode of action of the nonsteroidal anti-inflammatory drug ibuprofen in D. magna relates to interruption of eicosanoid biosynthesis, which reduces fecundity (Heckmann et al, 2008), where both prostanoids and lipoxygenase products appear to be important agents in oogenesis and embryogenesis (Medeiros et al, 2004).It was recently reported that the exposure of MF to Daphnia oocytes during late ovarian development causes the oocytes to develop into males, whereas only females are produced from control, unexposed animals (Mu and Leblanc, 2004;Ikuno et al, 2008). These results suggest that MF may act as a sex determinant.…”

Adverse Effects of Herbicides on Freshwater Zooplankton

“…Very recently, cDNA microarray-related techniques have been successfully used to address transcriptional responses of D. magna to different environmental toxicants, including pharmaceuticals, heavy-metals, pesticides and PAHs Heckmann et al, 2008;Soetaert et al, 2006Soetaert et al, , 2007Watanabe et al, 2007).…”

Approaching the evolutionary advantage of ancillary types of haemoglobin in Daphnia magna by simulation of oxygen supply

“…Among the daphnids, which play an important role in ecological research, toxicology and environmental monitoring, and in the emerging fields of ecological and toxicological genomics (Poynton et al, 2007;Eads et al, 2008;Heckmann et al, 2008;Shaw et al, 2008), the euryoxic species D. magna stands out due to the striking induction of Hb synthesis upon exposure to environmental oxygen deficiency (Fox, 1948;Fox et al, 1951;Kobayashi and Hoshi, 1982;Tokishita et al, 1997;Zeis et al, 2003;Gorr et al, 2004). The hypoxic induction of Hb synthesis is associated with a differing expression of globin genes, giving rise to macromolecules of altered subunit composition and enhanced oxygen affinity (Kobayashi et al, 1988;Kobayashi et al, 1994;Kimura et al, 1999;Zeis et al, 2003;Gorr et al, 2004;Lamkemeyer et al, 2005).…”