title: An investigation of endocrine disrupting effects and toxic mechanisms modulated by benzo[a]pyrene in female scallop Chlamys farreri.
abstract: The purpose of this study was to investigate the endocrine disrupting effects induced by benzo[a]pyrene (B[a]P) and explore the underlying mechanisms in mollusks. In this study, sexually mature female Chlamys farreri were exposed to benzo[a]pyrene for 10 days at four different concentrations as 0, 0.025, 0.5 and 10 μg/L. Sex steroids were identified and quantified by electrochemiluminescence immunoassay (ECLIA) method and results showed that exposure to B[a]P exerts great suppression on 17β-estradiol, testosterone production and disrupts progesterone levels in ovary. Transcription of genes were detected and measured by real-time RT-PCR. It showed that at day 10 B[a]P inhibited 3 β-HSD, CYP17 and 17β-HSD mRNA expression in a dose-dependent manner, which suggests that they could be potential targets of B[a]P that disrupt steroidogenic machinery. Moreover, 0.025 μg/L B[a]P activated transcription of aryl hydrocarbon receptor (AHR), AHR nuclear translocator (ARNT), CYP1A1 and estrogen receptor (ER), while 10 μg/L B[a]P suppressed all of them. The consistency of their responses to B[a]P exposure implies that AHR action may be involved in invertebrate CYP regulation and ER transcription despite of unknown mechanisms. Additionally, B[a]P exposure could induce ovarian impairment and developmental delay in C. farreri. Overall, sensitivity of C. farreri to endocrine disruption and toxicity suggests that C. farreri is a suitable species for study of endocrine-disrupting effects in marine invertebrates. This study will form a solid basis for a realistic extrapolation of endocrine disrupting effects across taxonomic groups and phyla.
authors.affiliation: The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, PR China.
authors.forename: Shuangmei
authors.initials: S
authors.lastname: Tian
authors.forename: Luqing
authors.initials: L
authors.lastname: Pan
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D052244:Endocrine Disruptors / Q000633:toxicity*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006066:Gonads / Q000187:drug effects; D049897:Pectinidae / Q000187:drug effects*; D013256:Steroids / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D052244:Endocrine Disruptors; D013256:Steroids; D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene
keywords: AHR; Benzo[a]pyrene; Chlamys farreri; ER; Endocrine disruption; Steroidogenesis