کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5764127 1625913 2017 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mercury (II) impairs nucleotide excision repair (NER) in zebrafish (Danio rerio) embryos by targeting primarily at the stage of DNA incision
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم آبزیان
پیش نمایش صفحه اول مقاله
Mercury (II) impairs nucleotide excision repair (NER) in zebrafish (Danio rerio) embryos by targeting primarily at the stage of DNA incision
چکیده انگلیسی
Mercuric ion (Hg2+) is the most prevalent form of inorganic Hg found in polluted aquatic environment. As inhibition of DNA damage repair has been proposed as one of the mechanisms of Hg2+-induced genotoxicity in aquatic animals and mammalian cells, this study explored the susceptibility of different stages of nucleotide excision repair (NER) in zebrafish (Danio rerio) embryos to Hg2+ using UV-damaged DNA as the repair substrate. Exposure of embryos at 1 h post fertilization (hpf) to HgCl2 at 0.1-2.5 μM for 9 h caused a concentration-dependent inhibition of NER capacity monitored by a transcription-based DNA repair assay. The extracts of embryos exposed to 2.5 μM Hg2+ almost failed to up-regulate UV-suppressed marker cDNA transcription. No inhibition of ATP production was observed in all Hg2+-exposed embryos. Hg2+ exposure imposed either weak inhibitory or stimulating effects on the gene expression of NER factors, while band shift assay showed the inhibition of photolesion binding activities to about 40% of control in embryos treated with 1-2.5 μM HgCl2. The damage incision stage of NER in zebrafish embryos was found to be more sensitive to Hg2+ than photolesion binding capacity due to the complete loss of damage incision activity in the extracts of embryos exposed to 1-2.5 μM Hg2+. NER-related DNA incision was induced in UV-irradiated embryos based on the production of short DNA fragments matching the sizes of excision products generated by eukaryotic NER. Pre-exposure of embryos to Hg2+ at 0.1-2.5 μM all suppressed DNA incision/excision in UV-irradiated embryos, reflecting a high sensitivity of DNA damage incision/excision to Hg2+. Our results showed the potential of Hg2+ at environmental relevant levels to disturb NER in zebrafish embryos by targeting primarily at the stage of DNA incision/excision.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Aquatic Toxicology - Volume 192, November 2017, Pages 97-104
نویسندگان
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