The role of okadaic acid (OA) in the defense system of the marine demosponge Suberites domuncula against symbiotic/parasitic annelids was examined. Bacteria within the mesohyl produced okadaic acid at concentrations between 32 ng/g and 58 ng/g of tissue (wet weight). By immunocytochemical methods and by use of antibodies against OA, we showed that the toxin was intracellularly stored in vesicles.
View Article and Find Full Text PDFSponges (phylum Porifera) are the phylogenetically oldest metazoa; as filter feeders, they are abundantly exposed to marine microorganisms. Here we present data indicating that the demosponge Suberites domuncula is provided with a recognition system for gram-negative bacteria. The lipopolysaccharide (LPS)-interacting protein was identified as a receptor on the sponge cell surface, which recognizes the bacterial endotoxin LPS.
View Article and Find Full Text PDFSponges (phylum Porifera) are sessile marine filter feeders that have developed efficient defense mechanisms against foreign attackers such as viruses, bacteria, or eukaryotic organisms. Protected by a highly complex immune system, as well as by the capacity to produce efficient antiviral compounds (e.g.
View Article and Find Full Text PDFSponges (phylum Porifera), known to be the richest producers among the metazoans of bioactive secondary metabolites, are assumed to live in a symbiotic relationship with microorganisms, especially bacteria. Until now, the molecular basis of the mutual symbiosis, the exchange of metabolites for the benefit of the other partner, has not been understood. We show with the demosponge Suberites domuncula as a model that the sponge expresses under optimal aeration conditions the enzyme tyrosinase, which synthesizes diphenols from monophenolic compounds.
View Article and Find Full Text PDFSponges live in a symbiotic relationship with microorganisms, especially bacteria. Here we show, using the demosponge Suberites domuncula as a model, that the sponge expresses the enzyme tyrosinase which synthesizes diphenols from monophenolic compounds. It is assumed that these products serve as carbon source for symbiotic bacteria to grow.
View Article and Find Full Text PDFThe investigations were performed with the eggs of the sea urchin speciesSphaerechinus granularis Lam. They were kept at 22° C under continuous aeration for up to 45 hours with stirring to compensate for sedimentation. 1.
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