Growth Inhibition and Altered Gene Transcript Levels in Earthworms (Eisenia fetida) Exposed to 2,2′,4,4′-Tetrabromodiphenyl Ether

Abstract

The toxic effects of the ubiquitous pollutant 2,2 0 ,4,4 0

Responses of growth inhibition and antioxidant gene expression in earthworms ( Eisenia fetida ) exposed to tetrabromobisphenol A, hexabromocyclododecane and decabromodiphenyl ether

“…In the present research, the expression of Hsp70 gene was significantly up-regulated when earthworms were exposed to TBBPA at concentrations of 50-200 mg/kg dw and HBCD at 400 mg/ kg dw, but no variation when exposed to BDE 209. The results are contrary to the research in earthworms exposed to BDE 47 (Xu et al, 2015) and in aquatic animals exposed to 4-nonylphenol, 4-t-octylpheno (Rhee et al, 2009), carbon tetrachloride and fenitrothion (Lee et al, 2006), but are in agreement with researches on up-regulation of Hsp70 gene expression in copepod exposed to bisphenol A (Rhee et al, 2009), in earthworms induced by the exposure of heavy metals (Homa et al, 2007). These results all provide evidence that the Hsp70 gene expression is involved in oxidative stress responses.…”

“…Previous reports have shown the up-regulation of CAT expression level in oysters exposed to cadmium (Jo et al, 2008), in earthworms exposed to AHTN (Chen et al, 2011a) to detoxify the oxidative stress, and its downregulation in earthworms exposed to BDE 47 (Xu et al, 2015) when the generated superfluous ROS exceeds the capacity of scavenging ROS by CAT. In the present research, there is no variation of CAT gene expression in the earthworms in all the TBBPA, HBCD and BDE 209 treatments, indicating a balance of generation and scavenge of hydrogen peroxide radical in earthworms.…”

“…PBDEs are the most extensively investigated BFRs and evidences showed that some monomers of PBDEs significantly inhibited the growth of the earthworm (E. fetida). The authors found that the growth inhibition rates of E. fetida treated by 400 mg/kg dw BDE 47 reached 36.4% after 14-day exposure (Xu et al, 2015). BDE 71 (1000 mg/kg dw) had significant effects on growth (GI = 25%) on E. fetida after 14-day exposure .…”

“…Superoxide dismutase (SOD) converts superoxide radical to hydrogen peroxide, thereby protecting cells from the toxic effects of superoxide radical (Liu et al, 2011;Hackenberger et al, 2012). The up-regulation of SOD gene expression indicates an adaptive onset of the antioxidant defense system in zebrafish to methylmercury (Gonzalez et al, 2005), in earthworms exposed to BDE 47 (Xu et al, 2015) and tonalide (AHTN) (Chen et al, 2011b). In this study, the significant up-regulation (P b 0.01) of SOD expression level was observed in earthworms exposed to TBBPA at 50 mg/kg dw and to HBCD at 400 mg/kg dw, indicating that transcription of SOD might be stimulated by oxidative stress generated by superoxide anion radical and the enhanced SOD gene expression was required to protect earthworms from oxidative stress and to counteract ROS toxicity.…”

Acute Atrazine Exposure has Lasting Effects on Chemosensory Responses to Food Odors in Crayfish (Orconectes virilis)

“…Following ATR exposure, caspase three activation also may be used as a marker for sensory neuron death (Cowan et al 2001). Additionally, treatment with ATR may lead to altered gene transcript levels in chemosensory appendages as seen in earthworms (Eisenia fetida) exposed to 2,2 0 ,4,4 0 -tetrabromodiphenyl ether (Xu et al 2015). It is possible that long-term exposure to ATR activates cell death in chemosensory cells responsible for chemoreception of food and other odors.…”