TY - JOUR
T1 - Sublethal mechanisms of Pb and Zn toxicity to the purple sea urchin (Strongylocentrotus purpuratus) during early development
AU - Tellis, Margaret S.
AU - Lauer, Mariana M.
AU - Nadella, Sunita
AU - Bianchini, Adalto
AU - Wood, Chris M.
N1 - Funding Information:
This research was supported by an award from the International Development Research Centre (IDRC, Ottawa, Canada) and the Canada Research Chair Program to AB and CMW. CMW is supported by the Canada Research Chair Program. A. Bianchini is a Research Fellow from the Brazilian ‘Conselho Nacional de Desenvolvimento Científico e Tecnológico’ (CNPq, Proc. #304430/2009-9, Brasília, DF, Brazil), and is supported by the International Research Chair Program from IDRC. Financial support was also provided by CAPES (Coordenação de Aperfeiçoamento de Pessoal do Ensino Superior, Brasilia, DF, Brazil) grant (AB, P.I.) in the scope of the ‘Programa Ciências do Mar’ and by two NSERC CRD grants (CMW and Scott Smith, P.I.’s) with co-funding from the International Zinc Association (IZA) , the International Lead Zinc Research Organization (ILZRO) , the Nickel Producers Environmental Research Association (NiPERA) , the International Copper Association (ICA) , the Copper Development Association (CDA) , Teck Resources , and Vale Inco . Many thanks to Jasim Chowdhury and Eric Van Genderen for useful comments on the mansuscript.
PY - 2014/1
Y1 - 2014/1
N2 - In order to understand sublethal mechanisms of lead (Pb) and zinc (Zn) toxicity, developing sea urchins were exposed continuously from 3h post-fertilization (eggs) to 96h (pluteus larvae) to 55 (±2.4)μgPb/L or 117 (±11)μgZn/L, representing ~70% of the EC50 for normal 72h development. Growth, unidirectional Ca uptake rates, whole body ion concentrations (Na, K, Ca, Mg), Ca2+ ATPase activity, and metal bioaccumulation were monitored every 12h over this period. Pb exhibited marked bioaccumulation whereas Zn was well-regulated, and both metals had little effect on growth, measured as larval dry weight, or on Na, K, or Mg concentrations. Unidirectional Ca uptake rates (measured by 45Ca incorporation) were severely inhibited by both metals, resulting in lower levels of whole body Ca accumulation. The greatest disruption occurred at gastrulation. Ca2+ ATPase activity was also significantly inhibited by Zn but not by Pb. Interestingly, embryos exposed to Pb showed some capacity for recovery, as Ca2+ATPase activities increased, Ca uptake rates returned to normal intermittently, and whole body Ca levels were restored to control values by 72-96h of development. This did not occur with Zn exposure. Both Pb and Zn rendered their toxic effects through disruption of Ca homeostasis, though likely through different proximate mechanisms. We recommend studying the toxicity of these contaminants periodically throughout development as an effective way to detect sublethal effects, which may not be displayed at the traditional toxicity test endpoint of 72h.
AB - In order to understand sublethal mechanisms of lead (Pb) and zinc (Zn) toxicity, developing sea urchins were exposed continuously from 3h post-fertilization (eggs) to 96h (pluteus larvae) to 55 (±2.4)μgPb/L or 117 (±11)μgZn/L, representing ~70% of the EC50 for normal 72h development. Growth, unidirectional Ca uptake rates, whole body ion concentrations (Na, K, Ca, Mg), Ca2+ ATPase activity, and metal bioaccumulation were monitored every 12h over this period. Pb exhibited marked bioaccumulation whereas Zn was well-regulated, and both metals had little effect on growth, measured as larval dry weight, or on Na, K, or Mg concentrations. Unidirectional Ca uptake rates (measured by 45Ca incorporation) were severely inhibited by both metals, resulting in lower levels of whole body Ca accumulation. The greatest disruption occurred at gastrulation. Ca2+ ATPase activity was also significantly inhibited by Zn but not by Pb. Interestingly, embryos exposed to Pb showed some capacity for recovery, as Ca2+ATPase activities increased, Ca uptake rates returned to normal intermittently, and whole body Ca levels were restored to control values by 72-96h of development. This did not occur with Zn exposure. Both Pb and Zn rendered their toxic effects through disruption of Ca homeostasis, though likely through different proximate mechanisms. We recommend studying the toxicity of these contaminants periodically throughout development as an effective way to detect sublethal effects, which may not be displayed at the traditional toxicity test endpoint of 72h.
KW - Calcification
KW - Echinoderm
KW - Embryonic development
KW - Lead
KW - Spicule
KW - Toxicity
KW - Zinc
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U2 - 10.1016/j.aquatox.2013.11.004
DO - 10.1016/j.aquatox.2013.11.004
M3 - Article
C2 - 24326189
AN - SCOPUS:84890012277
VL - 146
SP - 220
EP - 229
JO - Aquatic Toxicology
JF - Aquatic Toxicology
SN - 0166-445X
ER -