Cellular and molecular aspects of metal sequestration and toxicity in earthworms
| Autor: | Carole Winters, Stephen R. Stürzenbaum, A. John Morgan, Peter Kille |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | Invertebrate Reproduction & Development. 36:17-24 |
| ISSN: | 2157-0272 0792-4259 |
| DOI: | 10.1080/07924259.1999.9652673 |
| Popis: | Summary Metals accumulated within the tissues of earthworms are not homogeneously distributed. Rather, they are sequestered predominantly within the posterior alimentary fraction. The clear organotropism of non-essential metals is reinforced by the subcellular compartmentation of metals according to their known ligand-binding affinities: in earthworm chloragocytes and intestinal epithelial cells, in situ X-ray mapping in high-pressure frozen thin cryosections revealed that Pb, Zn, Ca and P were co-distributed in a discrete subcellular compartment, whilst Cd and S were co-distributed in another. Tissue homogenization and fractionation confirmed these differences. Cd is sequestered by cysteine-rich metallothionein isoforms; one isoform may be a true Cd-detoxification protein because it bears two putative glycosylation sites, and may thus deliver Cd to the lysosomal system for cytological isolation. Metal accumulation imposes metabolic costs that can reduce somatic growth and/or reproduction in earthworms: t... |
| Databáze: | OpenAIRE |
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