The aim of the research presented in this thesis was to investigate the cell biology behind the settlement and adhesion processes of biofouling algae. Using the fluorescent dye FM 1-43 in Ulva zoospores to follow membrane recycling, rapid mass membrane retrieval of FM 1-43-labelled plasma membrane was found to occur to an endosomal compartment during settlement. Biolistic delivery of dextran Oregon Green BAPTA-1 and Texas Red enabled ratiometric imaging with a 5-fold greater response to Ca\(^{2+}\)-ionophores than AM-ester Ca\(^{2+}\) indicators. During settlement, zoospores exhibited both localised and diffuse increases in cytosolic calcium implying a role in secretion of the adhesive. Secretion of redox-active substrates was detected using amperometry when settled spores were mechano-stimulated. Secretory events were similar to those seen in bovine chromaffin cells with the presence of foot signals in the recordings implying a role for a ‘fusion pore’ in exocytosis. Using DAF-FM DA nitric oxide (NO) production in Seminavis robusta was found to be 4-fold greater on a surface to which the cells adhered weakly than on a surface to which they attached more strongly. Increased NO reduced attachment strength and it is thought that NO may play a signalling and/or regulatory role in diatom adhesion.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:489821 |
Date | January 2008 |
Creators | Thompson, Stephanie Eleanor Mary |
Publisher | University of Birmingham |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | http://etheses.bham.ac.uk//id/eprint/194/ |
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