Search results for "Porifera"
showing 10 items of 196 documents
Origin of metazoan adhesion molecules and adhesion receptors as deduced from cDNA analyses in the marine sponge Geodia cydonium: a review.
1997
The phylogenetic relationships of the kingdom Animalia (Metazoa) have long been questioned. Whether the lowest eukaryotic multicellular organisms, the metazoan phylum Porifera (sponges), independently evolved multicellularity from a separate protist lineage (polyphyly of animals) or whether they were derived from the same protist group as the other animal phyla (monophyly) remains unclear. Analyses of the genes that are typical for multicellularity, e.g. those coding for adhesion molecules (galectin) and adhesion receptors (receptor tyrosine kinase, integrin receptor, receptors featuring scavenger receptor cysteine-rich domains) or elements involved in signal transduction pathways (G-protei…
Origin of neuronal-like receptors in Metazoa: cloning of a metabotropic glutamate/GABA-like receptor from the marine sponge Geodia cydonium.
1999
To date, no conclusive evidence has been presented for the existence of neuronal-like elements in Porifera (sponges). In the present study, isolated cells from the marine sponge Geodia cydonium are shown to react to the excitatory amino acid glutamate with an increase in the concentration of intracellular calcium [Ca2+]i. This effect can also be observed when the compounds L-quisqualic acid (L-QA) or L-(+)-2-amino-4-phosphonobutyric acid (L-AP-4) are used. The effect of L-QA and L-AP-4, both agonists for metabotropic glutamate receptors (mGluRs), can be abolished by the antagonist of group I mGluRs, (RS)-alpha-methyl-4-carboxyphenylglycine. These data suggest that sponge cells contain an mG…
Sponge Bcl-2 homologous protein (BHP2-GC) confers distinct stress resistance to human HEK-293 cells
2001
It is established that sponges, the phylogenetically oldest still extant phylum of Metazoa, possess key molecules of the apoptotic pathways, that is members from the Bcl-2 family and a pro-apoptotic molecule with death domains. Here we report on transfection studies of human cells with a sponge gene, GCBHP2. Sponge tissue was exposed to heat shock and tributyltin, which caused an upregulation of gene expression of GCBHP2. The cDNA GCBHP2 was introduced into human HEK-293 cells and mouse NIH-3T3 cells; the stable transfection was confirmed by the identification of the transcripts, by Western blotting as well as by immunofluorescence using antibodies raised against the recombinant polypeptide…
Sponge aggregation factor and sponge hemagglutinin: possible relationships between two different molecules.
1979
Abstract A lectin from the marine sponge GEODIA CYDONIUM was isolated and characterized. GEODIA lectin (GL) agglutinates human red blood cells irrespective of the ABO blood group and precipitates with a variety of D -galactose containing glycosubstances, i.e. certain snail galactans, bovine erythrocyte glycoprotein and PNEUMOCOCCUS type XIV polysaccharide. The only simple sugars inhibiting the GL-mediated hemagglutination were lactose and n -acetyl- D -galactosamine. GL was purified by affinity chromatography on Sepharose 4B almost to homogeneity as tested by polyacrylamide disc gel electrophoresis. Positive staining of the lectin band with Coomassie brilliant blue and PAS suggest that GL i…
Genome size and chromosomes in marine sponges [Suberites domuncula, Geodia cydonium]
1995
The genome size of the marine sponges Suberites domuncula and Geodia cydonium has been determined by flow cytofluorometric analysis using diamidino-phenylindole [DAPI]. Using human lymphocytes as reference the amount of DNA in cells from S. domuncula has been determined to be 3.7 pg and that of G. cydonium 3.3 pg. While no chromosomes could be identified in G. cydonium, the karyotype of the Suberites domuncula is 32 chromosomes in the diploid state. The size of the chromosomes was between 0.25 and 1.0 micron. No pronounced banding pattern was visible.
On the origin of Metazoan adhesion receptors: cloning of integrin alpha subunit from the sponge Geodia cydonium
1997
Integrins are prominent receptors known from vertebrates and the higher phyla of invertebrates. Until now, no evidence has been provided for the existence of integrins in the lowest Metazoa, the sponges (Porifera). We have isolated and characterized a cDNA clone encoding the alpha subunit of integrin from the marine sponge Geodia cydonium (GCINTEG). The open reading frame encodes a polypeptide of 1,086 residues (118 kDa). The intracellular domain features the sequence Tyr-Phe-x-Gly-Phe-Phe-x-Arg, which is different in one residue from the characteristic consensus pattern for integrin alpha subunits. We conclude that sponges, the oldest multicellular animal phylum, already utilize the struct…
Increased gene expression of a cytokine-related molecule and profilin after activation of Suberites domuncula cells with xenogeneic sponge molecule(s)
2000
Porifera (sponges) constitute the lowest metazoan phylum, Experiments examined whether sponges can recognize self/nonself molecules. Cells from the marine sponge Suberites domuncula were incubated with membranes from either S. domuncula or another marine sponge, Geodia cydonium, as well as with recombinant alpha-integrin from G. cydonium. The cells responded immediately with a rise of intracellular Ca2+ ([Ca-i(2+)]) if they were treated with membranes from G. cydonium but not after treatment by those from S. domuncula. This change of [Ca-i(2+)] was also recorded with G. cydonium alpha-integrin. In parallel, the expression of two genes was strongly upregulated; one codes for a cytokine-relat…
Immunological and biological identification of tumour necrosis-like factor in sponges: Endotoxin that mediates necrosis formation in xenografts
1992
Xenografts of the sponge Geodia cydonium in its closely related species G. rovinjensis resulted in a rapid rejection of the graft within a period of 5 days. We identified an immunoreactive tumour necrosis factor (TNF)-like activity in the xenograft (Mr of 30,000) two days after grafting. In-vivo injection of 5 micrograms human recombinant TNF-alpha induced cytotoxicity in sponge cells in the same pattern and time course as during natural xenograft rejection. Anti-TNF-alpha polyclonals were found to react with xenograft extracts, by Western blot analysis, as from day 2 after grafting. Using ELISA we detected the TNF-like activity from day 2 after grafting with peak levels at days 4 and 5, wh…
A novel galactose- and arabinose-specific lectin from the sponge Pellina semitubulosa: isolation, characterization and immunobiological properties.
1992
A new lectin from the sponge Pellina semitubulosa is derived which was extracted and purified to homogeneity. The purified lectin is probably a hexamer of polypeptide chains (each M(r) 34,000) which are covalently linked via disulfide linkages; the isoelectric point is 6.1. The lectin displays the following specificities: D-galactose (50% inhibition of hemagglutination at 0.2 mM) = L-arabinose (0.2 mM) greater than D-fucose (1.5 mM) greater than D-glucose (3.0 mM). It precipitates human erythrocytes (A1, A2, A1B, B, and O) with a titer between 2(8) and 2(11) and erythrocytes from sheep and rabbits with a titer between 2(5) and 2(10). The Pellina lectin displays a strong mitogenic effect on …
Cultivation of primmorphs from the marine sponge Suberites domuncula: morphogenetic potential of silicon and iron.
2002
Abstract Marine demosponges (phylum Porifera) are rich sources for potent bioactive compounds. With the establishment of the primmorph system from sponges, especially from Suberites domuncula , the technology to cultivate sponge cells in vitro improved considerably. This progress was possible after the elucidation that sponges are provided with characteristic metazoan cell adhesion receptors and extracellular matrix molecules which allow their cells a positioning in a complex organization pattern. This review summarizes recent data on the cultivation of sponges in aquaria and—with main emphasis—of primmorphs in vitro. It is outlined that silicon and Fe(+++) contribute substantially to the f…