Arrested development in Fucus spiralis (Phaeophyceae) germlings exposed to copper |
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Authors: | Peter Bond Murray Brown Roy Moate Martha Gledhill Stephen Hill Malcolm Nimmo |
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Affiliation: | 1. Department of Biological Sciences, University of Plymouth, Plymouth PL4 8AA, UK;2. Department of Environmental Sciences, University of Plymouth, Plymouth PL4 8AA, UK |
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Abstract: | Exposure of Fucus spiralis germlings to precise copper concentrations (0 to 844?nM?Cu2+) in chemically defined medium demonstrated a relationship between ultrastructural changes and growth retardation with increasing copper concentration. Electron-translucent vesicles, present in ova, which normally disappear after fertilization, accumulated in germlings exposed to Cu2+ above 10.6?nM, suggesting that copper may inhibit a metabolic pathway involved in cell wall formation which is initiated by fertilization. No membrane damage was observed during the exposure period. During a post-exposure period in copper-free medium, recovery occurred (rhizoid extension, apical hair formation) in germlings previously exposed to concentrations below 106?nM?Cu2+ and electron-translucent vesicles became granular and disappeared. It is proposed that the electron-translucent vesicles contain a cell wall precursor and that copper inhibits its incorporation into the cell wall, preventing growth and development of the zygote. |
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Keywords: | copper electron-translucent vesicles Fucus spiralis germlings ultrastructure |
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