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

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 *** 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 ***-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 *** tested concentrations of DE-83R also induced a down-regulation of thyroid receptor mRNA *** results demonstrated that technical decaBDE disrupted the thyroid system in *** *** of polybrominated diphenyl ethers （PBDEs）（sum of 39 congeners） in *** indicated that mean concentrations of total PBDEs in *** exposed to 1,10,100,1000 ng/L were 11.0,128.1,412.1,1400.2 ng/g wet weight,*** that PBDEs burden of *** 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

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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

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8 Å structure of the outer rings of the xenopus laevis nuclear pore complex obtained by cryo-EM and AI

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Protein & Cell 2022年第10期13卷 760-777页

作者： Linhua Tai Yun Zhu He Ren Xiaojun Huang Chuanmao Zhang Fei Sun National Key Laboratory of Biomacromolecules Institute of BiophysicsCAS Center for Excellence in BiomacromoleculesChinese Academy of SciencesBeijing 100101China The Ministry of Education Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology College of Life SciencesPeking UniversityBeijing 100871China Center for Biological Imaging Institute of BiophysicsChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Bioland Laboratory(Guangzhou Regenerative Medicine and Health Guangdong Laboratory) Guangzhou 510005China

The nuclear pore complex(NPC),one of the largest protein complexes in eukaryotes,serves as a physical gate to regulate nucleocytoplasmic ***,we determined the 8Åresolution cryo-electron microscopic(cryo-EM)structure of the outer rings containing nuclear ring(NR)and cytoplasmic ring(CR)from the xenopus laevis NPC,with local resolutions reaching 4.9Å.With the aid of AlphaFold2,we managed to build a pseudoatomic model of the outer rings,including the Y complexes and flanking *** this most comprehensive and accurate model of outer rings to date,the almost complete Y complex structure exhibits much tighter interaction in the hub *** addition to two copies of Y complexes,each asymmetric subunit in CR contains five copies of Nup358,two copies of the Nup214 complex,two copies of Nup205 and one copy of newly identified Nup93,while that in NR contains one copy of Nup205,one copy of ELYS and one copy of *** in-depth structural features represent a great advance in understanding the assembly of NPCs.

关键词： nuclear pore complex cryo-EM xenopus laevis AlphaFold2 nuclear ring cytoplasmic ring

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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.

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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

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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.

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Harmful Effects on African Clawed Frog （xenopus laevis） Reproduction as Expression of High Water Phosphates Levels

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Journal of Agricultural Science and Technology(A) 2015年第7期5卷 632-638页

作者： Marco Campolo Francesca Spano Maddalena Iannaccone Zoo delle Maitine Contrada delle Maitine 1 Pesco Sannita Benevento 82020 Italy Centro Veterinario Einaudi Via N. Colajanni 23A Bari 70125 Italy Consiglio Nazionale delle Ricerche lstituto di Biofisica Via de Marini 6 Genoa 16149 Italy Centro Veterinario I1Mondo Degli Animali Esotici Via S. Martino 67/r Genoa 16131 Italy

Amphibians are considered as reliable indicators of environmental quality. In Europe, a general decline of amphibians population parallels a worldwide decline, and some of the factors which are thought to be responsible to this decline are habitat loss, introduction of exotic species, disease and decreasing water quality. Recent investigations suggest that these eutrophic conditions may be associated with frog reproduction problems. Water quality criteria settled for the different species of amphibians do not currently exist, but in the present paper, the authors report their observation about water phosphate concentrations in association with hipofertility in African clawed frogs （xenopus laevis）. The study considered two different groups of African clawed frog showing hypofertility （22 patients） hosted in captivity. The animals were visited, and the filtration systems functionality and the water quality were checked, i.e., temperature, pH, ammonia, nitrite, nitrate, phosphates, hardness and alkalinity. In the first group, it was decided to perform ultrasound scans, parasitological tests on fecal samples, and microscopical/macroscopical examination, as well as microbiological analysis on collected oocytes. In the second group, only fecal samples were collected in order to perform parasitologiacal exams. No pathological findings were showed by veterinary tests. Water changes were carried out in both facilities and after two months, the fertility in African clawed frogs improved, evidencing the involvement of phosphates values in the onset of the problem and even more in its resolution. More studies are needed to further define this correlation.

关键词： xenopus laevis water phosphates level oocytes' quality.

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Potential Ecotoxic Effects of Polychlorinated Biphenyls on xenopus laevis

Potential Ecotoxic Effects of Polychlorinated Biphenyls on X...

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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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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

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Cloning and Analyzing of xenopus Mespo Promoter in Retinoic Acid Regulated Mespo Expression

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Acta Biochimica et Biophysica Sinica 2006年第11期38卷 759-764页

作者： Jin-Hu WANG Xiao-Yan DING* Institute of Biochemistry and Cell Biology,Shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,Graduate School of the Chinese Academy of Sciences,Shanghai 200031,China Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Graduate School of the Chinese Academy of SciencesShanghai 200031 China

During vertebrate embryogenesis,presomitic mesoderm cells enter a segmental program togenerate somite,a process termed ***,a member of the bHLH transcription factor family,plays important roles in this ***,how Mespo expression is regulated remains *** this question,we isolated a genomic DNA sequence containing 4317 bp of Mespo 5’ flanking regionin *** assays show that this upstream sequence has transcription *** assayshows that this genomic contig is sufficient to recapitulate the dynamic stage-and tissue-specific expressionpattern of endogenous Mespo from the gastrula to the tailbud *** further mapped a 326 bp DNAsequence responding to retinoic acid *** results shed light on how Mespo expression is regulated,and suggest that retinoic acid signaling pathways play roles in somitogenesis through regulating Mespo.

关键词： bHLH paraxial presomitic segmental tailbud xenopus laevis

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