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Thyroid disruption by technical decabromodiphenyl ether (DE-83R) at low concentrations in xenopus laevis

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Journal of Environmental Sciences 2010年第5期22卷 744-751页

作者： Xiaofei Qin Xijuan Xia Zhongzhi Yang Shishuai Yan Yaxian Zhao Rongguo Wei Yan Li Mi Tian Xingru Zhao Zhanfen Qin Xiaobai Xu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China Chinese Research Academy of Environmental Sciences Beijing 100012 China

Decabromodiphenyl ether （decaBDE）,as a flame retardant,is widely produced and used.To study the thyroid disruption by technical decaBDE at low concentrations,xenopus laevis tadpoles were exposed to technical decaBDE mixture DE-83R （1-1000 ng/L） in water from stage 46/47 （free swimming larvae,system of Nieuwkoop and Faber） to stage 62.DE-83R at concentration of 1000 ng/L significantly delayed the time to metamorphosis （presented by forelimb emergence,FLE）.Histological examination showed that DE83R at all tested concentrations caused histological alterations-multilayer follicular epithelial cell and markedly increased follicle size accompanied by partial colloid depletion and increase in the peripheral colloid vacuolation,in thyroid glands.All tested concentrations of DE-83R also induced a down-regulation of thyroid receptor mRNA expression.These results demonstrated that technical decaBDE disrupted the thyroid system in X.laevis tadpoles.Analysis of polybrominated diphenyl ethers （PBDEs）（sum of 39 congeners） in X.laevis indicated that mean concentrations of total PBDEs in X.laevis exposed to 1,10,100,1000 ng/L were 11.0,128.1,412.1,1400.2 ng/g wet weight,respectively.Considering that PBDEs burden of X.laevis tadpoles was close to PBDEs levels in amphibians as reported in previous studies,our study has raised new concerns for thyroid disruption in amphibians of technical decaBDE at environmentally relevant concentrations.

关键词： decabromodiphenyl ether xenopus laevis thyroid disruption metamorphosis thyroid hormone receptor

Low concentrations of atrazine,glyphosate,2,4-dichlorophenoxyacetic acid,and triadimefon exposures have diverse effects on xenopus laevis organ morphogenesis

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Journal of Environmental Sciences 2010年第9期22卷 1305-1308页

作者： Jenny R.Lenkowski Gabriela Sanchez-Bravo Kelly A.McLaughlin Department of Biology Tufts University

Many chemicals are released into the environment, and chemical contamination has been suggested as a contributing factor to amphibian declines. To add to a growing body of knowledge about the impact of individual chemicals on non-target organisms, we examined the specificity of deformities induced by exposure to four pesticides （atrazine, 2,4-dichloropheoxyacetic acid （2,4-D）, triadimefon, and glyphosate） in the model amphibian species, xenopus laevis. We focused on the period of organ morphogenesis, as it is frequently found to be particularly sensitive to chemical exposure yet also commonly overlooked. We found similar levels of intestine malformations and edemas, as well as disruption of skeletal muscle, in atrazine and triadimefon exposed tadpoles. The effects of 2,4-D were only apparent at the highest concentrations we examined; glyphosate did not induce dramatic malformations at the concentrations tested. While researchers have shown that it is important to understand how chemical mixtures affect non-target organisms, our results suggest that it is first crucial to determine how these chemicals act independently in order to be able to identify consequences of individual pesticide exposure.

关键词： amphibian pesticide organ morphogenesis teratogenesis toxicology xenopus laevis

Distinct expression profiles of transcriptional coactivators for thyroid hormone receptors during xenopus laevis metamorphosis

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Cell Research 2003年第6期13卷 459-464页

作者： BINDU D PAUL National Institutes of Health Laboratory of Gene Regulation and Development National Institute of Child Health and Human Development Bldg. USA.

The biological effects of thyroid hormone (T3) are mediated by the thyroid hormone receptor (TR). Amphibian metamorphosis is one of the most dramatic processes that are dependent on T3. T3 regulates a series of orchestrated developmental changes, which ultimately result in the conversion of an aquatic herbivorous tadpole to a terrestrial carnivorous frog. T3 is presumed to bind to TRs, which in turn recruit coactivators, leading to gene activation. The best-studied coactivators belong to the p160 or SRC family. Members of this family include SRC1/ NCoA-1, SRC2/TIF2/GRIP1, and SRC3/pCIP/ACTR/AIB-l/RAC-3/TRAM-1. These SRCs interact directly with liganded TR and function as adapter molecules to recruit other coactivators such as p300/CBP. Here, we studied the expression patterns of these coactivators during various stages of development. Amongst the coactivators cloned in xenopus laevis, SRC3 was found to be dramatically upregulated during natural and T3-induced metamorphosis, and SRC2 and p300 are express

关键词： transcription coactivators thyroid hormone receptor xenopus laevis metamorphosis histone acetylation.

IRE1α knockdown rescues tunicamycin-induced developmental defects and apoptosis in xenopus laevis

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The Journal of Biomedical Research 2014年第4期28卷 275-281页

作者： Li Yuan Jin Yu Xinxin Li Jiaojiao Feng Chenyang Yin Xinru Wang Department of Biochemistry and Molecular Biology Nanjing Medical University Department of Hematology Friendship hospital of yili kazakh prefecture Key Laboratory of Reproductive Medicine Institute of ToxicologyNanjing Medical University

Inositol requiring enzyme-1 （IRE1） is highly conserved from yeasts to humans. Upon endoplasmic reticulum （ER） stress, IRE1 activates X-box-binding protein 1 （XBP1） by unconventional splicing of XBP1 mRNA, which activates unfolded protein response （UPR） to restore ER homeostasis. In mice, IRE1α plays an essential role in extraembryonic tissues. However, its precise action during the early stage of development is unknown. In this study, the gain and loss-of-function analyses were used to investigate the function of xenopus IRE1α （xIRE1α）. The effects of xIRE1α during embryo development were detected with RT-PCR and whole mount in situ hybridization. ER stress was induced by tunicamycin. The apoptofic cells were measured by TUNNEL assays. Although both gain and loss of xlRE1α function had no significant effect on xenopus embryogenesis, knockdown of xIRE1α could rescue tunicamycin-induced developmental defects and apoptosis. The finding indicates that xIRE1α is not required for embryogenesis but is required for tunicamycin-induced developmental defects and apoptosis in xenopus laevis.

关键词： IRE1α xenopus laevis tunicamycin developmental defects

Effect of antikeratin microinjection on the embryonic development of xenopus laevis

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Cell Research 1993年第2期3卷 147-156页

作者： YU HAOJIAN, JINGWU XIE, FENG CAO, JINHUA LIANGDepartment of Biology, Beijing University, Beijing100871, China Department of Biology Beijing University Beijing China

Anti-keratin monoclonal antibody AF5 was introduced into fertilized eggs of xenopus laevis., and its effects on embryonic development were studied. Survival rate of the antikeratin-injected embryos was much lower (only 35.76% at gastrula) than that of the control (74.85% at gastrula), in which embryos were injected with mouse IgG. Most of survivors in the experimental series showed aberrant external appearance. On the other hand, in cleavage stage, ie 2-7 h after fertilization, immunohistochemical staining of embryos showed that the experimental embryos were mostly keratin negative, while embryos of the control ones were keratin positive. When introducing this antikeratin into one cell of a 2-cell embryo, only the uninjected half of the embryo continued its development while the other half could not develop at all. These results suggested that intact keratin cytoskeleton in early embryos is indispensable to the embryonic development of xenopus laevis.

关键词： xenopus laevis fertilized egg keratin cytoskeleton monoclonal antibody microinjection.

爪蟾(xenopus laevis)的细胞质对基因功能的作用

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中国科学(B辑化学生物学农学医学地学) 1987年第2期 161-167页

作者：于豪建史长平牛满江北京大学生物系中国科学院发育生物学研究所北京美国Temple大学生物系

野生型爪蟾的色素基因是显性,a~P白化型的色素基因是隐性,野生型卵子与白化型精子受精,在第二极体形成之际,用紫外线照射卵子使卵核失活,从而产生异源的单倍体杂种,这些杂种发育时,眼的黑色素和皮肤上黑色素细胞发生时期同野生型一致,... 详细信息

野生型爪蟾的色素基因是显性,a~P白化型的色素基因是隐性,野生型卵子与白化型精子受精,在第二极体形成之际,用紫外线照射卵子使卵核失活,从而产生异源的单倍体杂种,这些杂种发育时,眼的黑色素和皮肤上黑色素细胞发生时期同野生型一致,比白化型早得多,色素细胞的数目和颜色介于野生型和白化型之间,当白化型蝌蚪的色素细胞最后消退时,杂种蝌蚪仍有许多色素细胞。所以,杂种的色素细胞发育和维持归因于野生型卵细胞质的作用。染色体检查是取尾尖压片,计数,野生型和白化型二倍体为36个染色体,杂种单倍体为18个染色体。

关键词：细胞质胞浆雄核发育孤雄发育 xenopus laevis 二倍体两倍体鲤鱼卵染色体检查黑色素细胞野生型金鱼观赏鱼类眼色素杂种杂交种爪蟾基因功能

Potential Ecotoxic Effects of Polychlorinated Biphenyls on xenopus laevis

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Potential Ecotoxic Effects of Polychlorinated Biphenyls on X...

Gut microbiota dysbiosis involves in host non-alcoholic fatty liver disease upon pyrethroid pesticide exposure

作者： Zhan-Fen Qin, Jing-Ming Zhou, Lin Cong, Xiao-Bai Xu The State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China, 100085

＜正＞We examined potential ecotoxic effects of PCB3,PCB5, Aroclor1254, and Aroclor 1242 on xenopus laevis. Tadpoles were exposed to polychlorinated biphenyls （PCBs） from stage 46/47 （system of Nieuwkoop and Faber） to complete metamorphosis. We for the first time demonstrated forelimb-malformations caused by PCBs （malformation rate exceeding 70%）. The malformed forelimbs were fixed in the adduction-backwards rotation position and cannot move. Therefore, malformed male frogs are destined for no offspring because mey cannot grasp the females with forelimbs to mate. Alcian blue-alizarin red double staining indicated that the forelimb malformation resulted from the shoulder abnormality. Compared with the normal shoulder joint, the proximal humerus with the humerus interrotated 90° in the abnormal shoulder joint Moreover, testes of exceeding one-third male frogs with PCBs-exposure exhibited feminization to different degrees in gross morphology and histology, with less or abnormal spermatogonia and occytes. Gonadal abnormalities would directly lead to reproductive dysfunction and population decline. These results suggest that PCBs have potential ecotoxic effects on amphibian populations. We infer that PCBs could play roles in amphibian malformations and population declines, at least in heavy PCBs-polluted sites.

关键词： Polychlorinated biphenyls xenopus laevis Malformation Gonad Amphibian population

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Environmental Science and Ecotechnology 2022年第3期11卷 83-92页

作者： Meng Li Tingting Liu Teng Yang Jiaping Zhu Yunqian Zhou Mengcen Wang Qiangwei Wang Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects Institute of Pesticide and Environmental ToxicologyZhejiang UniversityHangzhou310058China Agricultural Technical Institute The Ohio State UniversityWoosterOH44691USA Global Education Program for AgriScience Frontiers Graduate School of AgricultureHokkaido UniversitySapporo060-8589Japan

A growing body of evidence has demonstrated the significance of the gut microbiota in host health,while the association between gut microbiota dysbiosis and multiple diseases is yet elusive in the scenario of exposure to widely used pesticides.Here,we show that gut microbiota dysbiosis involves in host's abnormal lipid metabolism and consequently the non-alcoholic fatty liver disease in xenopus laevis upon exposure to cis-bifenthrin,one of the most prevalent pyrethroid insecticides in the world.With the guidance of gut microbiota analysis,we found that cis-bifenthrin exposure significantly perturbed the gut microbial community,and the specific taxa that served as biomarkers were identified.Metabolomics profiling and association analysis further showed that a significant change of intestinal metabolites involved in lipid metabolic pathways were induced along with the microbiota dysbiosis upon exposure to cis-bifenthrin.Detailed investigation showed an altered functional regulation of lipids in the liver after cis-bifenthrin exposure and the accumulation of lipid droplets in hepatocytes.Specifically,a change in deoxycholic acid alters bile acid hepatoenteral circulation,which affects lipid metabolism in the liver and ultimately causes the development of fatty liver disease.Collectively,these findings provide novel insight into the gut microbiota dysbiosis upon pesticide exposure and their potential implication in the development of chronic host diseases related to liver metabolic syndrome.

关键词： Pyrethroid xenopus laevis Metabolic disorders Dysbiosis gut microbiota

Optimization of the T3-induced xenopus metamorphosis assay for detecting thyroid hormone signaling disruption of chemicals

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Journal of Environmental Sciences 2017年第2期29卷 314-324页

作者： Xiaofang Yao Xiaoying Chen Yinfeng Zhang Yuanyuan Li Yao Wang Zongming Zheng Zhanfen Qin Qingdong Zhang School of Environment and Resource Southwest University of Science and TechnologyMianyang 621010China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

T3-induced xenopus metamorphosis is an ideal model for detecting thyroid hormone（TH）signaling disruption of chemicals. To optimize the T3-induced xenopus assay and improve its sensitivity and reproducibility, we intend to develop quantitatively morphological endpoints and choose appropriate concentrations and exposure durations for T3 induction.xenopus laevis at stage 52 were exposed to series of concentrations of T3（0.31–2.5 nmol/L）for 6 days. By comparing morphological changes induced by T3, we propose head area,mouth width, unilateral brain width/brain length, and hindlimb length/snout-vent length as quantitative parameters for characterizing T3-induced morphological changes, with body weight as a parameter for indicating integrated changes. By analyzing time-response curves, we found that following 4-day exposure, T3-induced grossly morphological changes displayed linear concentration–response curves, with moderate morphological changes resulting from 1.25 nmol/L T3 exposure. When using grossly morphological endpoints to detect TH signaling disruption, we propose 4 days as exposure duration of T3, with concentrations close to 1.25 nmol/L as induction concentrations. However, it is appropriate to examine morphological and molecular changes of the intestine on day 2 due to their early response to T3. The quantitative endpoints and T3 induction concentrations and durations we determined would improve the sensitivity and the reproducibility of the T3-induced xenopus metamorphosis assay.

关键词： Thyroid hormone signaling Disruption xenopus laevis T3 induction Morphological endpoints TH-response gene expression