Silica deposition in Demosponges: spiculogenesis in Crambe crambe

  title={Silica deposition in Demosponges: spiculogenesis in Crambe crambe},
  author={Mar{\'i}a Jes{\'u}s {\'U}riz and Xavier Turon and Mikel A. Becerro},
  journal={Cell and Tissue Research},
Abstract. 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. Axial filaments occur free in the mesohyl, in close contact with sclerocytes, and are triangular in cross section, with an internal silicified core. The unit… 

Formation of siliceous spicules in the marine demosponge Suberites domuncula

Immunohistological analysis has shown that silicatein exists in the axial canal (axial filament) and on the surface of the spicules, suggesting that they grow by apposition, and it is demonstrated that the enzymic reaction of silicatesin is inhibited by anti-silicatein antibodies.

Histochemical and Electron Microscopic Analysis of Spiculogenesis in the Demosponge Suberites domuncula

Data indicate that species-specific formation of spicules involves a network of (diffusible) regulatory factor(s) controlling enzymatic silica deposition; this mineralization process proceeds on a galectin/collagen organic matrix.

Some aspects of silica deposition in lithistid demosponge desmas

Differentiation of morphological forms of silica in desmas, which is at least genus‐specific, clearly supports the polyphyletic nature of lithistid sponges.

Structural characterization of siliceous spicules from marine sponges.

Intra-epithelial spicules in a homosclerophorid sponge

The findings indicate that the cellular mechanisms of spicule production vary across sponges and reveal the need for a careful re-examination of the hitherto monophyletic state attributed to biosilicification within the phylum Porifera.

Comparative study of spiculogenesis in demosponge and hexactinellid larvae

  • S. Leys
  • Biology
    Microscopy research and technique
  • 2003
The elaboration and organization of the spicules differ markedly in cellular and syncytial sponges and appear to be an outcome of the very distinct cellular differentiation and larval morphogenesis that occur in each of these groups.

Insights into the structure and morphogenesis of the giant basal spicule of the glass sponge Monorhaphis chuni

Detailed examinations with transmitted light and epifluorescence microscopy, SEM, solid state NMR analysis, FTIR and X-ray analysis and staining of Monorhaphis chuni basal spicules are presented to better understand its structure and function.

Analysis of silicatein gene expression and spicule formation in the demosponge Amphimedon queenslandica

Investigation of the process of spiculogenesis in the different developmental stages of the demosponge Amphimedon queenslandica, and the evolution and developmental expression of the silicatein gene family in relation to spicule formation, suggests that these genes have preserved an ancestral gene structure common to both families in both marine and freshwater sponges.

Fiber diffraction study of spicules from marine sponges

A synchrotron radiation fiber diffraction structural study of the axial filament of siliceous spicules from two species of marine sponges indicated that the protein units in the filament of both samples were highly organized.



Form and Distribution of Silica in Sponges

In a number of lines of demosponges and hexactinellids there is a tendency toward the deposition of secondary deposits of silica on the basic spicule forms with the resulting formation of rigid skeletal frameworks composed of fused or interlocking spicules.

On the Structure of Calcareous Sponge Spicules

Calcareous sponge spicules are composed of calcite (Sollas 1885) admixed with magnesium, sodium, strontium and sulphate. The magnesium content is species-specific and has been found to vary from

A reconsideration of the relationship between polyaxonid and monaxonid spicules in Demospongiae: new data from the genera Crambe and Discorhabdella (Porifera)

From the overall results here presented, the tetraxonid spicule, presently considered by most authors as the primitive morphotype, as well as some monaxons, could be considered as evolving from a polyaxial form.

Silicification Processes in Sponges: Geodia Asters and the Problem of Morphogenesis of Spicule Shape

The pattern of development of complex siliceous structures (asters) in Geodia cydonium involve the formation of short, terminal processes which then become fused together and finally form a star-shaped pattern, difficult to invoke the presence of a centrally located silicification center as a basis for this sequence of morphogenesis.

Ultrastructure and Deposition of Silica in Sponges

Sponges, the most primitive multicellular animals, are able to concentrate and precipitate three mineral elements: iron, calcium, and silicon. Iron forms small granules deposited on and within the


  • J. GrossZ. SokalM. Rougvie
  • Biology
    The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society
  • 1956
Two morphologically distinct forms of spongin fibers were demonstrated to be members of the collagen class, structurally by x-ray diffraction and electron microscopy, and chemically by their hydroxyproline and glycine content as well as by the general amino acid pattern.

Decline in Mesozoic reef-building sponges explained by silicon limitation

These findings indicate that silicon limitation, probably aggravated in shallow waters by the diatom burst around the Cretaceous–Tertiary boundary, may have forced neritic sponges with desmas to either lighten their skeletons or move to deeper, silicon-rich environments.

Localization of Two Brominated Metabolites, Aerothionin and Homoaerothionin, in Spherulous Cells of the Marine Sponge Aplysina fistularis (=Verongia thiona)

Energy dispersive X-ray microanalysis was used to localize the two brominated natural products in the tissues of a marine demosponge, Aplysina fistularis, for the first localization of any secondary metabolite at the cellular or sub-cellular level in any marine invertebrate.