Bio-sintering processes in hexactinellid sponges: Fusion of bio-silica in giant basal spicules from Monorhaphis chuni☆

Müller, Wernér E.G.; Wang, Xiaohong; Burghard, Zaklina; Bill, Joachim; Krasko, Anatoli; Boreiko, Alexandra; Schloßmacher, Ute; Schröder, Heinz C.; Wiens, Matthias

doi:10.1016/j.jsb.2009.08.003

Cited by 48 publications

(39 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Framboids precipitate from porewater supersaturated with respect to pyrite and iron monosulphides; euhedral crystals precipitate from porewater oversaturated with respect to pyrite, but undersaturated with respect to iron monosulphides (Raiswell 1982, Passier et al 1997, Sweeney & Kaplan 1973, Taylor et al 2000. Sponge spicules are composed of amorphous silica (Müller et al 2009), which is transformed during early diagenesis in opal-CT (Steiner et al fig. 6).…”

Section: F E H Imentioning

confidence: 99%

“…Modern siliceous sponges have a skeleton composed of siliceous spicules which are composed of amorphous silica. Each spicule has a central protein (silicatein) filament that triggers silica deposition (Müller et al 2009, Shimizu et al 1998. Such central filaments are also visible in some fossil sponge spicules of the earliest Cambrian Sancha Fauna from Hunan Province .…”

mentioning

confidence: 99%

See 1 more Smart Citation

Taphonomy of Cambrian (Stage 3/4) sponges from Yunnan (South China)

Forchielli¹,

Steiner²,

Hu³

et al. 2012

Bull. Geosci.

View full text Add to dashboard Cite

Sponges are one of the major faunistic components of the Burgess Shale-type fossil Lagerstätte of Chengjiang (Cambrian Stage 3, South China). Although pyritization is often invoked as a key process linked to the early diagenetic preservation in the Chengjiang Fauna, the unweathered specimens analyzed lack evidence of pyrite. Energy dispersive X-ray (EDX) analyses of these specimens show a robust and continuous film of organic carbon. Most of the Chengjiang sponges underwent extensive weathering and diagenetic alteration. The biogenic silica transformed in opal-CT (crystalline type) was dissolved leaving a cavity, successively filled by different minerals, or possibly underwent dissolution under acidic water conditions combined with oxygenation. This resulted in clay and iron oxide replication (framboids or micro-sized crystals) of the sponge spicules. Organic material of the original cellular layer is preserved as depleted organic carbon film.•

show abstract

Section: F E H Imentioning

confidence: 99%

mentioning

confidence: 99%

Taphonomy of Cambrian (Stage 3/4) sponges from Yunnan (South China)

Forchielli¹,

Steiner²,

Hu³

et al. 2012

Bull. Geosci.

View full text Add to dashboard Cite

show abstract

“…Müller et al (19)(20)(21) reported that antibodies against silicatein α from the demosponge Suberites domuncula cross-reacted with a 27-kDa protein in the giant anchor spicules of Monorhaphis chuni and with a 24-kDa protein in the spicules of Crateromorpha meyeri. Mass spectrometric analysis of a fragment from the M. chuni 27-kDa protein demonstrated that it contained sequences corresponding to the silicateins from demosponges (22). Silicatein sequences deduced from cDNA clones from M. chuni and C. meyeri contain the characteristic catalytic amino acid triad, serinehistidine-asparagine (19,21).…”

mentioning

confidence: 99%

Glassin, a histidine-rich protein from the siliceous skeletal system of the marine sponge Euplectella , directs silica polycondensation

Shimizu

Amano

Bari

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The hexactinellids are a diverse group of predominantly deep sea sponges that synthesize elaborate fibrous skeletal systems of amorphous hydrated silica. As a representative example, members of the genus Euplectella have proved to be useful model systems for investigating structure-function relationships in these hierarchically ordered siliceous network-like composites. Despite recent advances in understanding the mechanistic origins of damage tolerance in these complex skeletal systems, the details of their synthesis have remained largely unexplored. Here, we describe a previously unidentified protein, named "glassin," the main constituent in the water-soluble fraction of the demineralized skeletal elements of Euplectella. When combined with silicic acid solutions, glassin rapidly accelerates silica polycondensation over a pH range of 6-8. Glassin is characterized by high histidine content, and cDNA sequence analysis reveals that glassin shares no significant similarity with any other known proteins. The deduced amino acid sequence reveals that glassin consists of two similar histidine-rich domains and a connecting domain. Each of the histidine-rich domains is composed of three segments: an amino-terminal histidine and aspartic acid-rich sequence, a proline-rich sequence in the middle, and a histidine and threonine-rich sequence at the carboxyl terminus. Histidine always forms HX or HHX repeats, in which most of X positions are occupied by glycine, aspartic acid, or threonine. Recombinant glassin reproduces the silica precipitation activity observed in the native proteins. The highly modular composition of glassin, composed of imidazole, acidic, and hydroxyl residues, favors silica polycondensation and provides insights into the molecular mechanisms of skeletal formation in hexactinellid sponges.T he hexactinellids are a circumglobal group of predominantly deep sea sponges. Exhibiting a diverse array of morphologies, the skeletal systems of hexactinellids, which are composed of amorphous hydrated silica (the other silica-forming sponge class is the Demospongiae), range in structural complexity from loose aggregations of individual skeletal elements (spicules) to complex, hierarchically ordered lattices. Hexactinellids have evolved the ability to colonize either rocky substrates or soft sediments and exhibit remarkable skeletal modifications to accomplish these feats (1). For example, the sediment-dwelling hexactinellids produce bundles of long fibrillar anchor spicules that form robust holdfast structures. These anchor spicules exhibit surprising flexibility and damage tolerance and have served as useful model systems for investigating high performance silica-based organic-inorganic biological composites (2-4). In one representative genus, Euplectella (Fig. 1), the constituent spicules are assembled into a highly regular cylindrical lattice that exhibits multiple levels of structural hierarchy spanning from the nanoscale to the macroscale. The lattice is composed of two interpenetrating grid-like networks of no...

show abstract

“…In hexactinellids, e.g., in Euplectella aspergillum, the interaction between the spicules is even more obvious. Their spicules grow, on average, to larger sizes [20] and often fuse to form a continuous super-scaffold [21] (Figure 2 "radiate" pattern of the spiral type, the spicules are arranged in bundles that have been termed radiating skeletal fibers (rf). Within the fibers, the tissue is organized and harbors the aquiferous canal system (as).…”

Section: Organization Of the Spicules Within The Sponge Bodymentioning

confidence: 99%