کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6382667 1625963 2013 27 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Differential acclimation of a marine diatom to inorganic mercury and methylmercury exposure
ترجمه فارسی عنوان
انطباق دیفرانسیل دیاتومهای دریایی با جیوه معدنی و قرار گرفتن در معرض متیل کرچک
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم آبزیان
چکیده انگلیسی
Aquatic organisms originating from metal polluted water may exhibit differences in their sensitivity to metals, but the underlying physiological mechanisms resulting in such responses have not been well reported. In the present study, a marine diatom Thalassiosira weissflogii was chronically exposed to different inorganic mercury (Hg(II), 0.5 and 5 μg Hg/L) or methylmercury (MeHg, 0.02 and 0.4 μg Hg/L) concentrations for over 18 generations. We then quantified the changes in the Hg(II) or MeHg sensitivity, Hg accumulation, subcellular distribution, as well as thiol compound induction in the diatoms. We found an unchanged tolerance to Hg(II) but an enhanced tolerance to MeHg in the preconditioned T. weissflogii. The underlying mechanisms may be related to the changes in cellular mercury accumulation and the detoxification ability of the cells. Specifically, exposure to high-Hg(II) led to increased metal distribution in cellular debris fraction, as well as the induction of a variety of non-protein thiol compounds, but the uptake kinetics was not significantly modified by Hg(II) exposure. Instead, exposure to high-MeHg decreased the mercury uptake rate along with the synthesis of glutathione (GSH) and (γ-EC)2-Gly (PC2). All these responses contributed to the different tolerance developments between Hg(II) and MeHg. This study suggests that moderation of Hg bioavailability was probably more important than internal detoxification in the development of Hg acclimation in marine diatoms.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Aquatic Toxicology - Volumes 138–139, 15 August 2013, Pages 52-59
نویسندگان
, ,