Cell biology of settlement and adhesion processes of biofouling algae

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 Ca²⁺-ionophores than AM-ester Ca²⁺ 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.

Name dc:type.qualificationname

d_ph

Level dc:type.qualificationlevel

d_ph

Grantor dc:publisher.institution

University of Birmingham

Year dc:date.issued

2008

Author dc:creator

• Thompson, Stephanie Eleanor Mary

• QH301 Biology

Repository record dc:identifier.uri

http://etheses.bham.ac.uk//id/eprint/194/2/Decl_IS_Thompson08PhD.jpg

OAI identifier oai:identifier

oai:etheses.bham.ac.uk:194