Zebra Fish

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Claudia Wiegand - One of the best experts on this subject based on the ideXlab platform.

  • attenuating effects of natural organic matter on microcystin toxicity in Zebra Fish danio rerio embryos benefits and costs of microcystin detoxication
    Environmental Toxicology, 2006
    Co-Authors: Jimena Cazenave, Claudia Wiegand, Maria De Los Angeles Bistoni, Elke Zwirnmann, Daniel Alberto Wunderlin

    To contribute to the understanding of joined factors in the environment, impact of pure microcystins (-RR and -LF) on Zebra Fish (Danio rerio) embryos were investigated individually and in combination with a natural organic matter (NOM). The applied NOM was a reverse osmosis isolate from Lake Schwarzer See (i.e., Black Lake, BL-NOM). Teratogenic effects were evaluated through changes in embryonic development within 48 h of exposure. Detoxication activities were assessed by the activities of phase II biotransformation enzymes, soluble and microsomal glutathione S-transferase (s, mGST). Oxidative stress was assessed by determining both the production of hydrogen peroxide and by analyzing the activities of the antioxidative enzymes, guajacol peroxidase (POD), catalase (CAT), glutathione peroxidase (GPx), and the glutathione restoring enzyme glutathione reductase (GR). Energetic costs were evaluated by determining contents of fat, carbohydrates, and proteins in both exposed and control embryos. BL-NOM attenuated toxic effects of MC-LF and MC-RR verified by less pronounced teratological effects within 24 h, in particular, as well as less rise in the activity of s-GST, when compared with embryos exposed to either pure toxins or in combination with organic matter. BL-NOM also diminished oxidative effects caused by MC-LF; however, it failed to attenuate oxidative stress caused by MC-RR. Content of lipids was significantly reduced in exposed embryos following a trend similar to that obtained with teratological and enzymatic assays confirming the attenuating effect of BL-NOM. Physiological responses to microcystins and NOM required energetic costs, which were compensated to the expense of the energy resources of the yolk, which in turn might affect the normal development of embryos.

  • effects of enteric bacterial and cyanobacterial lipopolysaccharides and of microcystin lr on glutathione s transferase activities in Zebra Fish danio rerio
    Aquatic Toxicology, 2002
    Co-Authors: J.h. Best, F.b. Eddy, Claudia Wiegand, Stephan Pflugmacher, James S Metcalf, Geoffrey A Codd

    Abstract Cyanobacteria (blue-green algae) can produce a variety of toxins including hepatotoxins e.g. microcystins, and endotoxins such as lipopolysaccharides (LPS). The combined effects of such toxins on Fish are little known. This study examines the activities of microsomal (m) and soluble (s) glutathione S-transferases (GST) from embryos of the Zebra Fish, Danio rerio at the prim six embryo stage, which had been exposed since fertilisation to LPS from different sources. A further aim was to see how activity was affected by co-exposure to LPS and microcystin-LR (MC-LR). LPS were obtained from Salmonella typhimurium, Escherichia coli, a laboratory culture of Microcystis CYA 43 and natural cyanobacterial blooms of Microcystis and Gloeotrichia. Following in vivo exposure of embryos to each of the LPS preparations, mGST activity was significantly reduced (from 0.50 to between 0.06 and 0.32 nanokatals per milligram (nkat mg−1) protein). sGST activity in vivo was significantly reduced (from 1.05 to between 0.19 and 0.22 nkat mg−1 protein) after exposure of embryos to each of the cyanobacterial LPS preparations, but not in response to S. typhimurium or E. coli LPS. Activities of both m- and sGSTs were reduced after co-exposure to MC-LR and cyanobacterial LPS, but only mGST activity was reduced in the S. typhimurium and E. coli LPS-treated embryos. In vitro preparations of GST from adult and prim six embryo D. rerio showed no significant changes in enzyme activity in response to the LPS preparations with the exception of Gloeotrichia bloom LPS, where mGST was reduced in adult and embryo preparations. The present study represents the first investigations into the effects of cyanobacterial LPS on the phase-II microcystin detoxication mechanism. LPS preparations, whether from axenic cyanobacteria or cyanobacterial blooms, are potentially capable of significantly reducing activity of both the s- and mGSTs, so reducing the capacity of D. rerio to detoxicate microcystins. The results presented here have wide ranging implications for both animal and human health.

  • uptake and effects of microcystin lr on detoxication enzymes of early life stages of the Zebra Fish danio rerio
    Environmental Toxicology, 1999
    Co-Authors: Claudia Wiegand, Stephan Pflugmacher, Axel Oberemm, Nanke Meems, Kenneth A Beattie, Christian E W Steinberg, Geoffrey A Codd

    The effects of cyanotoxins on Fish have been studied mainly in adults, rather than in early life stages which could be more sensitive or, in view of their immobility, more readily affected. The uptake of microcystin-LR by different early life stages of the Zebra Fish (Danio rerio) was investigated using 14C-labelled microcystin-LR. The effects on the activity of the detoxication enzymes, microsomal and soluble glutathione S-transferases (GST), and glutathione peroxidase (GP-X) were examined. There was a detectable uptake of microcystin from the first day of embryonic development up to 5 day old larvae. On average, an absorption of 0.5 ng microcystin for eggs and eleuthero-embryos was calculated over the entire exposure time. Because of the differences in volume of the eggs and eleuthero-embryos, there was an increase in the microcystin-LR concentration between these stages. In the eggs, approximately 25% of the medium concentration was found, and in eleuthero-embryos an equilibrium between Fish and medium was reached. The activity of the detoxication enzymes differed during ontogenesis, but the effects of activation and suppression of these enzymes were similar at all stages. Minor activation of the soluble GST was found and a marked activation of GP-X was evident. The reaction of the microsomal GST was not so obvious. These results showed that there was an uptake of microcystin-LR by early life stages of the Zebra Fish and that the detoxication system reacted to this toxin, possibly indicating the ability of the organism to metabolize microcystin-LR to a less harmful compound. Chronic toxic effects, such as reduction in growth, in such early life stages when organogenesis is not finished and hence the microcystin-LR affects not one single target organ but the whole organism, might be due to the increased energy demand of these detoxication processes. ©1999 John Wiley & Sons, Inc. Environ Toxicol 14: 89–95, 1999

Weiying Lin - One of the best experts on this subject based on the ideXlab platform.

Lijuan Zhao - One of the best experts on this subject based on the ideXlab platform.

  • influence of sublethal doses of acetamiprid and halosulfuron methyl on metabolites of Zebra Fish brachydanio rerio
    Aquatic Toxicology, 2017
    Co-Authors: Hong Zhang, Lijuan Zhao

    Acetamiprid, a neonicotinoid pesticide, is reported to have adverse sublethal effects on non-target beneficial organisms. Halosulfuron-methyl (HM), one of the most widely used herbicides in agriculture, has high ecotoxicity to aquatic plants and animals. In this study, a GC-MS-based metabolomics approach was used to investigate the toxicity of acetamiprid and HM. The Automated Mass Spectral Deconvolution and Identification System (AMDIS) software program and the retention index method were used to identify 51 metabolites in Zebra Fish (Brachydanio rerio). Changes in metabolites showed that acetamiprid and HM disturbed amino acid (e.g., leucine, valine, serine, glycine, proline, and alanine) metabolism, the TCA cycle (malic acid and fumaric acid), and the balance of neurotransmitters (glutamic acid, taurine, and glycine). The change in metabolites in the liver, head, and blood indicated that metabolites in the liver were more sensitive than those in the head and blood. Overall, on the basis of the change in metabolites, we identified a potential risk to Zebra Fish exposed to sublethal doses of acetamiprid and/or HM.

  • molecular cloning and functional characterization of mannose receptor in Zebra Fish danio rerio during infection with aeromonas sobria
    International Journal of Molecular Sciences, 2015
    Co-Authors: Feifei Zheng, Muhammad Asim, Jiangfeng Lan, Lijuan Zhao, Shun Wei, Nan Chen, Xiaoling Liu, Yang Zhou, Li Lin

    Mannose receptor (MR) is a member of pattern-recognition receptors (PRRs), which plays a significant role in immunity responses. Much work on MR has been done in mammals and birds while little in Fish. In this report, a MR gene (designated as zfMR) was cloned from Zebra Fish (Danio rerio), which is an attractive model for the studies of animal diseases. The full-length cDNA of zfMR contains 6248 bp encoding a putative protein of 1428 amino acids. The predicted amino acid sequences showed that zfMR contained a cysteine-rich domain, a single fibronectin type II (FN II) domain, eight C-type lectin-like domains (CTLDs), a transmembrane domain and a short C-terminal cytoplasmic domain, sharing highly conserved structures with MRs from the other species. The MR mRNA could be detected in all examined tissues with highest level in kidney. The temporal expression patterns of MR, IL-1β and TNF-α mRNAs were analyzed in the liver, spleen, kidney and intestine post of infection with Aeromonas sobria. By immunohistochemistry assay, slight enhancement of MR protein was also observed in the spleen and intestine of the infected Zebra Fish. The established Zebra Fish-A. sobria infection model will be valuable for elucidating the role of MR in Fish immune responses to infection.

Geoffrey L Hammond - One of the best experts on this subject based on the ideXlab platform.

  • sex hormone binding globulin in Fish gills is a portal for sex steroids breached by xenobiotics
    Endocrinology, 2008
    Co-Authors: Solange Miguelqueralt, Geoffrey L Hammond

    As in most vertebrates, plasma sex hormone-binding globulin (SHBG) is produced in Fish liver and regulates sex steroid access to target tissues. Low levels of SHBG mRNA are present in Zebra Fish gills but are unlikely to account for the high amounts of immunoreactive SHBG in filaments and lamellae. Although the uptake of steroids by Fish from water has been reported to correlate with their affinity for SHBG, it is not known how this occurs. Our studies of Zebra Fish SHBG have revealed its preference for biological active androgen (testosterone), as well as for androstenedione, a sex steroid precursor that also acts as a pheromone in some Fish. In addition to natural steroids, Zebra Fish SHBG has a high affinity for synthetic steroids, such as ethinylestradiol and progestins (levonorgestrel and norethindrone), that are present in waste water systems. Because steroids can pass across Fish gills, we examined whether SHBG serves as a portal for natural and synthetic steroids controlling their flux between the...

Min Peng - One of the best experts on this subject based on the ideXlab platform.