Results 131 to 140 of about 790 (166)

Mesostructure from Hydration Gradients in Demosponge Biosilica

Chemistry – A European Journal, 2014
AbstractOrganisms of the phylum Porifera, that is, sponges, utilize enzymatic hydrolysis to concatenate bioavailable inorganic silicon to produce lightweight, strong, and often flexible skeletal elements called spicules. In their optical transparency, these remarkable biomaterials resemble fused silica, despite having been formed under ambient marine ...
James R, Neilson, Nathan C, George, Meredith M, Murr, Ram, Seshadri, Daniel E, Morse   +4 more
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Silica deposition in Demosponges: spiculogenesis in Crambe crambe

Cell and Tissue Research, 2000
Transmission electron-microscopy images coupled with dispersive X-ray analysis of the species Crambe crambe have provided information on the process of silica deposition in Demosponges. Sclerocytes (megasclerocytes) lie close to spicules or surround them at different stages of growth by means of long thin enveloping pseudopodia.
M J, Uriz, X, Turon, M A, Becerro
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Biomineralization in living hypercalcified demosponges: Toward a shared mechanism? [PDF]

Journal of Structural Biology, 2013
Massive skeletons of living hypercalcified sponges, representative organisms of basal Metazoa, are uncommon models to improve our knowledge on biomineralization mechanisms and their possible evolution through time. Eight living species belonging to various orders of Demospongiae were selected for a comparative mineralogical characterization of their ...
Gilis, M., Grauby, O., Willenz, P., Dubois, P., Heresanu, V., Baronnet, A.   +5 more
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Unifying Design Strategies in Demosponge and Hexactinellid Skeletal Systems

The Journal of Adhesion, 2010
Biological systems are well known for their ability to construct remarkably complex and mechanically robust skeletal structures from a great diversity of minerals. One such example, silica, is widely used in the synthesis of skeletal elements (spicules) within the phylum Porifera (the sponges).
Weaver, M., Milliron, G.W., Allen, P., Miserez, A., Rawal, A., Garay, J., Thurner, P.-J., Seto, J., Mayzel, B., Friesen, L.J., Chmelka, F., Fratzl, P., Aizenberg, J., Dauphin, Y., Kisailus, D., Morse, D.E.   +15 more
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Hypercalcified demosponges and the end-Permian extinction

Global and Planetary Change, 2010
Abstract The hypothesis is presented here that the hypercalcified demosponges, characterized by a solid, largely external skeleton of spherulitic aragonite, or of high-Mg calcite, had symbiotic cyanobacteria, from the outset of their existence, that enabled them to precipitate their peculiar skeleton, and that both the skeleton and the cyanobacteria ...
exaly   +2 more sources

MicroRNA expression during demosponge dissociation, reaggregation, and differentiation and a evolutionarily conserved demosponge miRNA expression profile

Development Genes and Evolution, 2015
Demosponges share eight orthologous microRNAs (miRNAs), with none in common with Bilateria. Biological functions of these demosponge miRNAs are unknown. Bilaterian miRNAs are key regulators of cellular processes including cell cycle, differentiation, and metabolism.
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Regeneration rates of a sublittoral demosponge

Journal of the Marine Biological Association of the United Kingdom, 2002
The effect of water flow rate on the regeneration rate of the temperate sponge Cliona celata was investigated at two sites experiencing fast and slight current flow respectively at Lough Hyne, Co. Cork, Ireland. Faster regeneration rates were found in sponges living in high current areas which may be due to an increased amount of potential food ...
openaire   +1 more source

The GABAergic‐like system in the marine demosponge Chondrilla nucula

Microscopy Research and Technique, 2007
AbstractGamma‐amino butyric acid (GABA) is believed to be the principal inhibitory neurotransmitter in the mammalian central nervous system, a function that has been extended to a number of invertebrate systems. The presence of GABA in the marine demosponge Chondrilla nucula was verified using immunofluorescence detection and high‐pressure liquid ...
RAMOINO, PAOLA, GALLUS, LORENZO, PALUZZI S, RAITERI, LUCA, DIASPRO, ALBERTO GIOVANNI, FATO, MARCO MASSIMO, BONANNO, GIAMBATTISTA, TAGLIAFIERRO, GRAZIA, FERRETTI C, MANCONI R.   +9 more
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Comparative study of spiculogenesis in demosponge and hexactinellid larvae

Microscopy Research and Technique, 2003
AbstractSpicule deposition was studied by electron microscopy in fixed embryos and larvae of the haplosclerid sponge Reniera sp. and the hexactinellid Oopsacas minuta. Spicules form in centrally located vacuoles within cells and within syncytia, as in the adult sponges. In Reniera, scleroblasts differentiate from micromeres prior to gastrulation.
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Formation of siliceous spicules in the marine demosponge Suberites domuncula

Cell and Tissue Research, 2005
The siliceous skeleton of demosponges is constructed of spicules. We have studied the formation of spicules in primmorphs from Suberites domuncula. Scanning electron microscopy and transmission electron-microscopical (TEM) analyses have revealed, in the center of the spicules, an axial canal that is 0.3-1.6 microm wide and filled with an axial filament.
Werner E G, Müller, Matthias, Rothenberger, Alexandra, Boreiko, Wolfgang, Tremel, Andreas, Reiber, Heinz C, Schröder   +5 more
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