Reproductive Toxicity and Teratogenicity of Fluorene-9-bisphenol on Chinese Medaka (Oryzias sinensis): A Study from Laboratory to Field.

Fluorene-9-bisphenol (BHPF), a bisphenol A (BPA) substitute, has been increasingly used as a material in syntheses of polymers that are widely used in road markings, artificial tracks, coating floors, building paints, etc., increasing the likelihood of BHPF contamination in the aquatic environment due to its release from the products. However, to date, it is unknown whether it may have actual impacts on fish in real environments. In this study, a 105-day exposure experiment of BHPF at various concentrations (0.01, 0.1, 1, and 10 µg/L) on Chinese medaka (Oryzias sinensis) was performed under laboratory conditions and found decreased fecundity, such as lower egg qualities and quantities, retarded oogenesis, and atretic follicles in the fish and deformed eyes and bodies in its F1 generation. Toxico-transcriptome analyses showed that estrogen-responsive genes were significantly suppressed by BHPF, indicating that antagonist properties of BHPF on estrogen receptors might be causes for the decreased fecundity. Field investigations (Beijing) demonstrated that BHPF was detectable in 60% surface waters, with a mean concentration of 10.49 ± 6.33 ng/L, by gas chromatography-mass spectrometry, and similar effects in wild Chinese medaka were also observed, some of which the parameters were found to be obviously correlated with the BHPF levels in corresponding waters.

Genome and transcriptome of Chinese medaka (Oryzias sinensis) and its uses as a model fish for evaluating estrogenicity of surface water.

Ecological toxicity assessments of contaminants in aquatic environments are of great concern. However, a dilemma in ecological toxicity assessments often arises when linking the effects found in model animals in the laboratory and the phenomena observed in wild fishes in the field due to species differences. Chinese medaka (Oryzias sinensis), widely distributed in East Asia, is a satisfactory model animal to assess aquatic environment in China. Here, we domesticated this species and assembled its genome (814 Mb) using next-generation sequencing (NGS). A total of 21,922 high-confidence genes with 41,306 transcripts were obtained and annotated, and their expression patterns in tissues were determined by RNA-sequencing. Six mostly sensitive biomarker genes, including vtg1, vtg3, vtg6, zp3a.2, zp2l1, and zp2.3 to estrogen exposure were screened and validated in the fish exposed to concentrations of estrone (E1), 17ß-estradiol (E2), and estriol (E3) under laboratory condition. Field investigations were then performed to evaluating the gene expression of biomarkers in wild Chinese medaka and levels of E1, E2, and E3 in the fish habitats. It was found that in 40 sampling sites, the biomarker genes were obviously highly expressed in the wild fish from about half sites, and the detection frequencies of E1, E2, and E3, were 97.5%, 42.5%, and 45% with mean concentrations of 82.48, 43.17, 52.69 ng/L, respectively. Correlation analyses of the biomarker gene expressions in the fish with the estrogens levels which were converted to EEQs showed good correlation, indicating that the environmental estrogens and estrogenicity of the surface water might adversely affect wild fishes. Finally, histologic examination of gonads in male wild Chinese medaka was performed and found the presence of intersex in the fish. This study facilitated the uses of Chinese medaka as a model animal for ecotoxicological studies.

Determination of the Role of Microcystis aeruginosa in Toxin Generation Based on Phosphoproteomic Profiles.

Microcystis aeruginosa is the most common species responsible for toxic cyanobacterial blooms and is considered a significant contributor to the production of cyanotoxins, particularly the potent liver toxins called microcystins. Numerous studies investigating Microcystis spp. blooms have revealed their deleterious effects in freshwater environments. However, the available knowledge regarding the global phosphoproteomics of M. aeruginosa and their regulatory roles in toxin generation is limited. In this study, we conducted comparative phosphoproteomic profiling of non-toxic and toxin-producing strains of M. aeruginosa. We identified 59 phosphorylation sites in 37 proteins in a non-toxic strain and 26 phosphorylation sites in 18 proteins in a toxin-producing strain. The analysis of protein phosphorylation abundances and functions in redox homeostasis, energy metabolism, light absorption and photosynthesis showed marked differences between the non-toxic and toxin-producing strains of M. aeruginosa, indicating that these processes are strongly related to toxin generation. Moreover, the protein-protein interaction results indicated that BJ0JVG8 can directly interact with the PemK-like toxin protein B0JQN8. Thus, the phosphorylation of B0JQN8 appears to be associated with the regulatory roles of toxins in physiological activity.

[Spatiotemporal variation patterns of water quality of Taoranting Lake, Beijing of China].

By the methods of cluster analysis, discriminant analysis, and factor analysis, this paper studied the spatiotemporal variations of water quality of Taoranting Lake, a typical eutrophic urban landscape lake in Beijing, from March to November 2011. At temporal scale, the water quality of the Lake could be grouped into three periods which corresponded to the rainy season, normal season, and dry season in Beijing, respectively, reflecting an obvious temporal variation. At spatial scale, the water quality of the Lake at five sampling sites could be grouped into two groups, implying the different pollution degree. Water temperature, pH, transparency (SD), CODMn, total suspended solid (TSS) , and Chl-a content were the main factors affecting the temporal variation of the water quality, and the eutrophication of the water body was mainly controlled by the water temperature and Chl-a, total nitrogen, and total phosphorous contents. The effects of TSS and organic pollution should be also paid more attention.

The estrogenic potential of salicylate esters and their possible risks in foods and cosmetics.

Salicylate esters (SEs), a class of chemicals extensively used as flavor and fragrance additives in foods, beverages and a wide variety of consumer products, are suspected to have estrogenic activity based on chemical analysis of in silica molecular docking. We evaluated the estrogenic potentials of phenyl salicylate (PhS), benzyl salicylate (BzS), phenethyl salicylate (PES), ethyl salicylate (ES) and methyl salicylate (MS) using an in vitro human estrogen receptor α (hERα)-coactivator recruiting assay and in vivo immature rodent uterotrophic bioassays. We found that PhS, BzS and PES showed obvious in vitro hERα agonistic activities; BzS in particular exhibited a higher estrogenic activity compared to bisphenol A (BPA). The uterine weights were significantly increased in mice treated with 11.1, 33.3, 100 and 300 mg/kg/day BzS and 33.3mg/kg/day PES and rats treated with 3.7, 11.1, 33.3 and 100mg/kg/day BzS for 3 days (P<0.05). Finally, we transformed the daily intakes and the dermal exposures of SEs in the real world into estradiol equivalent concentrations (EEQs). We found that the EEQ of BzS daily intake in consumers in the U.S. and the EEQs of dermal BzS and PES exposure among high-volume users worldwide were higher than the maximum secure daily estradiol intake recommended by the U.S. Food and Drug Administration (FDA). In particular, the EEQ for dermal BzS exposure was up to 162 ng EEQ/kg, which is 3.3 times higher than the maximal acceptable daily E(2) intake recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Effect of temperature on the sorption and desorption of perfluorooctane sulfonate on humic acid.

Sorption and desorption of perfluorooctane sulfonate (PFOS) on humic acid at different temperatures were studied. It was found that the sorption process could be modeled with power kinetic equation very well, suggesting that diffusion predominated the sorption of PFOS on the humic acid. The sorption capacity was doubled when the temperature increased from 5 to 35 degrees C, and thermodynamics parameters deltaG0 was calculated to be -7.11 to -5.04 kJ/mol, AHo was 14.2 kJ/mol, and deltaS0 was 69.5 J/(mol x K), indicating that the sorption was a spontaneous, endothermic, and entropy driven process. Desorption hysteresis occurred at all studied temperatures which suggested that humic acid may be an important sink of PFOS in the environment.

Effect of salinity and sediment characteristics on the sorption and desorption of perfluorooctane sulfonate at sediment-water interface.

This study investigated the influence of solution salinity, pH and the sediment characteristics on the sorption and desorption of perfluorooctane sulfonate (PFOS). The results showed that the sorption of PFOS onto sediment increased by a factor of 3 as the CaCl(2) concentration increased from 0.005 to 0.5 mol L(-1) at pH 7.0, and nearly 6 at pH 8.0. Desorption hysteresis occurred over all salinity. The thermodynamic index of irreversibility (TII) values increased with increasing concentration of CaCl(2). Maximum irreversibility was found in the sorption systems with CaCl(2) in the concentration of 0.5 mol L(-1). The results suggested that PFOS can be largely removed from the water with increasing salinity, and get trapped onto sediments irreversibly. These phenomena could be explained by salting-out effect and Ca-bridging effect. Studies also suggested that the content of total organic carbon is the dominant psychochemical properties of sediment controlling the sorption of PFOS.

Effect of cationic and anionic surfactants on the sorption and desorption of perfluorooctane sulfonate (PFOS) on natural sediments.

Sorption and desorption of PFOS at water-sediment interfaces were investigated in the presence of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), and an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS). CTAB remarkably enhanced the sorption of PFOS on the sediment. In contrast, the influence of SDBS to the sorption of PFOS was concentration dependent. Two contrasting factors were responsible for the phenomenon. One was the sorption of the surfactant itself to the sediment, which enhanced the sorption of PFOS. The other was the increase in solubility of PFOS caused by the adding of surfactants, which decreased the sorption of PFOS. SDBS had a much lower sorption capacity, but rather strong ability to increase the solubility of PFOS. High levels of SDBS remarkably reduced the sorption of PFOS on the sediment. These results imply that cationic and anionic surfactants may have contrast impacts on the distribution and transport of PFOS in the environment.