English  |  正體中文  |  简体中文  |  Items with full text/Total items : 27308/39152
Visitors : 2448127      Online Users : 122
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search
LoginUploadHelpAboutAdminister

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/48764

Title: 汞與砷對斑馬魚胚胎中紫外線傷害DNA辨識及修復活性之影響
Detrimental Effects of Mercury(II) and Arsenite on DNA Mismatch and UV-damaged-DNA Binding Activities in Zebrafish (Danio rerio) Embryos
Authors: Vikram Paul
維克朗
Contributors: 國立臺灣海洋大學:生命科學暨生物科技學系
Keywords: CPD;6-4PP;Zebrafish embryos;Arsenite;Mercury(II)
CPD;6-4PP;斑馬魚胚胎;;
Date: 2016
Issue Date: 2018-08-22T06:31:06Z
Abstract: 摘要 本研究探討重金屬於環境中可能出現濃度下對斑馬魚胚胎中DNA傷害辨識作用之影響。 研究方法以凝膠電泳阻滯實驗檢測鎘、三價砷及二價汞處理斑馬魚胚胎九小時後,胚胎中辨識紫外線扭曲DNA與DNA錯誤配對活性之改變。胚胎在二價汞於1與3μM濃度下作用後,紫外線傷害產生之正環丁烷嘧啶雙體及(6-4)光合產物之辨識活性能力下降,此活性於3μM汞處理胚胎中降至未處理組之30%以下,而鎘處理並未產生明顯影響。三價砷於5至20μM濃度下未對紫外線傷害辨識作用產生清楚效應,但此金屬卻使胚胎中辨識寡核酸環錯誤配對的活性上升40%左右,卻也輕微抑制G-T錯誤配對活性,顯示三價砷對辨識不同錯誤配對之蛋白有差異性影響。全覆式原位雜交分析僅觀察到三價砷輕微抑制斑馬魚錯誤配對的辨識蛋白MSH6之基因表現,但仍需後續工作加以確認。
ABSTRACT DNA Mismatch repair (MMR) and Nucleotide Excision Repair (NER) are the two DNA repair pathways that respectively corrects base mispairs generated during replication and removes helix distorting lesions such as UV- induced dipyrimidine photoproducts. Arsenic (As), Mercury (Hg) and Cadmium (Cd) are well known genotoxicants present in the aquatic environment. Inhibition of DNA damage repair has been proposed as one of the mechanisms of metal-induced genotoxicity. Because the potentials of Cd and Hg (II) to inhibit MMR in zebrafish embryos by disturbing the step of DNA mismatch recognition have been shown, this study explored the effects of Arsenite (AsIII) on DNA mismatch binding activities in Zebrafish embryos. Effects of the three metals on UV-damaged-DNA binding activities were also studied. Compared to Cd at 1 to 3 µM, both cyclobutane pyrimidine dimer (CPD) and (6-4) photoproduct (6-4 PP) binding activities in zebrafish embryos were found to be much more sensitive to Hg (II) at the same concentrations, suggesting that Hg (II) is a strong NER inhibitor. Conversely, both CPD and 6-4 PP binding activities were not affected by As(III) unless in embryos exposed to 10 to 20 µM of this ion, which are within the typical levels found in drinking water in contaminated areas. As (III) exposure failed to inhibit G-T and 2-loop DNA mismatch binding activities in zebrafish embryos and As (III) even caused a weak up-regulation of loop-specific binding capacity. Analysis of the gene expression of MutS homolog 6(MSH6), an important eukaryotic DNA mismatch binding factor, in zebrafish tissues by whole mount in situ hybridization suggested a weak inhibition of gene activity in embryos exposed to 10 to 20 µM As(III). Whether As (III) inhibits MSH6 gene expression in zebrafish embryos, however, awaits further investigation.
URI: http://ethesys.lib.ntou.edu.tw/cgi-bin/gs32/gsweb.cgi?o=dstdcdr&s=G0010236044.id
http://ntour.ntou.edu.tw:8080/ir/handle/987654321/48764
Appears in Collections:[生命科學暨生物科技學系] 博碩士論文

Files in This Item:

File Description SizeFormat
index.html0KbHTML13View/Open


All items in NTOUR are protected by copyright, with all rights reserved.

 


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback