title: Accumulation, subcellular distribution and toxicity of inorganic mercury and methylmercury in marine phytoplankton.
abstract: We examined the accumulation, subcellular distribution, and toxicity of Hg(II) and MeHg in three marine phytoplankton (the diatom Thalassiosira pseudonana, the green alga Chlorella autotrophica, and the flagellate Isochrysis galbana). For MeHg, the inter-species toxic difference could be best interpreted by the total cellular or intracellular accumulation. For Hg(II), both I. galbana and T. pseudonana exhibited similar sensitivity, but they each accumulated a different level of Hg(II). A higher percentage of Hg(II) was bound to the cellular debris fraction in T. pseudonana than in I. galbana, implying that the cellular debris may play an important role in Hg(II) detoxification. Furthermore, heat-stable proteins were a major binding pool for MeHg, while the cellular debris was an important binding pool for Hg(II). Elucidating the different subcellular fates of Hg(II) and MeHg may help us understand their toxicity in marine phytoplankton at the bottom of aquatic food chains.
authors.affiliation: Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wu
authors.forename: Wen-Xiong
authors.initials: WX
authors.lastname: Wang
mesh_terms: D000460:Chlorophyta / Q000187:drug effects / Q000378:metabolism; D017377:Diatoms / Q000187:drug effects / Q000378:metabolism; D020387:Food Chain; D058087:Haptophyta / Q000187:drug effects / Q000378:metabolism; D008628:Mercury / Q000378:metabolism* / Q000633:toxicity; D008767:Methylmercury Compounds / Q000378:metabolism* / Q000633:toxicity; D010839:Phytoplankton / Q000187:drug effects / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury