title: Multilevel ecotoxicity assessment of polycyclic musk in the earthworm Eisenia fetida using traditional and molecular endpoints.
abstract: The ecotoxicity assessment of galaxolide (HHCB) and tonalide (AHTN) was investigated in the earthworm Eisenia fetida using traditional and novel molecular endpoints. The median lethal concentration (LC(50)) for 7-day and 14-day exposures was 573.2 and 436.3 μg g(-1) for AHTN, and 489.0 and 392.4 μg g(-1) for HHCB, respectively. There was no observed significant effect on the growth rate of E. fetida after a 28-day exposure except that at the highest concentration (100 μg g(-1)) of AHTN and HHCB, whereas a significant decrease of cocoon production was found in earthworms exposed to 50 and 100 μg g(-1). To assess molecular-level effect, the expression of encoding antioxidant enzymes and stress protein genes were investigated upon sublethal exposures using the quantitative real time PCR assay. The expression level of SOD, CAT and calreticulin genes was up-regulated significantly, while the level of annetocin (ANN) and Hsp70 gene expression was down-regulated in E. fetida. Importantly, the level of ANN expression had a significant positive correlation with the reproduction rate of earthworms. Furthermore, the lowest observed effect concentration (LOECs) of ANN expression level was 3 μg g(-1) for AHTN and 10 μg g(-1) for HHCB, suggesting that ANN gene expression can serve as a more sensitive indicator of exposure to AHTN and HHCB than traditional endpoints such as cocoon production. The transcriptional responses of these genes may provide early warning molecular biomarkers for identifying contaminant exposure, and the data obtained from this study will contribute to better understand the toxicological effect of AHTN and HHCB.
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.forename: Shengguo
authors.initials: S
authors.lastname: Xue
authors.forename: Qixing
authors.initials: Q
authors.lastname: Zhou
authors.forename: Xiujie
authors.initials: X
authors.lastname: Xie
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001578:Benzopyrans / Q000633:toxicity*; D037282:Calreticulin / Q000235:genetics; D002374:Catalase / Q000235:genetics; D054750:Ecotoxicology / Q000379:methods; D005786:Gene Expression Regulation; D005819:Genetic Markers; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D007447:Invertebrate Hormones / Q000235:genetics; D007928:Lethal Dose 50; D009835:Oligochaeta / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D010456:Peptides, Cyclic / Q000235:genetics; D012098:Reproduction / Q000187:drug effects; D012987:Soil; D012989:Soil Pollutants / Q000633:toxicity; D013482:Superoxide Dismutase / Q000235:genetics; D013764:Tetrahydronaphthalenes / Q000633:toxicity*; D036401:Toxicity Tests, Chronic; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D001578:Benzopyrans; D037282:Calreticulin; D005819:Genetic Markers; D018840:HSP70 Heat-Shock Proteins; D007447:Invertebrate Hormones; D010456:Peptides, Cyclic; D012987:Soil; D012989:Soil Pollutants; D013764:Tetrahydronaphthalenes; C033119:galaxolide; C085335:annetocin; C033116:acetyl methyl tetramethyl tetralin; D002374:Catalase; D013482:Superoxide Dismutase