scholarly journals A Nature’s Curiosity: The Argonaut “Shell” and Its Organic Content

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 839
Author(s):  
Morgane Oudot ◽  
Ira Ben Shir ◽  
Asher Schmidt ◽  
Laurent Plasseraud ◽  
Cédric Broussard ◽  
...  
Keyword(s):  
General Scheme ◽  
Complex Mixture ◽  
Organic Matrix ◽  
Biochemical Properties ◽  
Organic Content ◽  
Molecular Tools ◽  
Molluscan Shell ◽  
Shell Matrix ◽  
Coiled Structure

Molluscs are known for their ability to produce a calcified shell resulting from a genetically controlled and matrix-mediated process, performed extracellularly. The occluded organic matrix consists of a complex mixture of proteins, glycoproteins and polysaccharides that are in most cases secreted by the mantle epithelium. To our knowledge, the model studied here—the argonaut, also called paper nautilus—represents the single mollusc example where this general scheme is not valid: the shell of this cephalopod is indeed formed by its first dorsal arms pair and it functions as an eggcase, secreted by females only; furthermore, this coiled structure is fully calcitic and the organization of its layered microstructures is unique. Thus, the argonautid shell appears as an apomorphy of this restricted family, not homologous to other cephalopod shells. In the present study, we investigated the physical and biochemical properties of the shell of Argonauta hians, the winged argonaut. We show that the shell matrix contains unusual proportions of soluble and insoluble components, and that it is mostly proteinaceous, with a low proportion of sugars that appear to be mostly sulfated glycosaminoglycans. Proteomics performed on different shell fractions generated several peptide sequences and identified a number of protein hits, not shared with other molluscan shell matrices. This may suggest the recruitment of unique molecular tools for mineralizing the argonaut’s shell, a finding that has some implications on the evolution of cephalopod shell matrices.

scholarly journals The ‘Shellome’ of the Crocus Clam Tridacna crocea Emphasizes Essential Components of Mollusk Shell Biomineralization

2021 ◽  
Vol 12 ◽  
Author(s):  
Takeshi Takeuchi ◽  
Manabu Fujie ◽  
Ryo Koyanagi ◽  
Laurent Plasseraud ◽  
Isabelle Ziegler-Devin ◽  
...  
Keyword(s):  
Organic Matrix ◽  
The Other ◽  
Matrix Proteins ◽  
Shell Formation ◽  
Molluscan Shell ◽  
Shell Matrix ◽  
Essential Components ◽  
Shell Matrix Proteins ◽  
Shell Organic Matrix ◽  
Tridacna Crocea

Molluscan shells are among the most fascinating research objects because of their diverse morphologies and textures. The formation of these delicate biomineralized structures is a matrix-mediated process. A question that arises is what are the essential components required to build these exoskeletons. In order to understand the molecular mechanisms of molluscan shell formation, it is crucial to identify organic macromolecules in different shells from diverse taxa. In the case of bivalves, however, taxon sampling in previous shell proteomics studies are focused predominantly on representatives of the class Pteriomorphia such as pearl oysters, edible oysters and mussels. In this study, we have characterized the shell organic matrix from the crocus clam, Tridacna crocea, (Heterodonta) using various biochemical techniques, including SDS-PAGE, FT-IR, monosaccharide analysis, and enzyme-linked lectin assay (ELLA). Furthermore, we have identified a number of shell matrix proteins (SMPs) using a comprehensive proteomics approach combined to RNA-seq. The biochemical studies confirmed the presence of proteins, polysaccharides, and sulfates in the T. crocea shell organic matrix. Proteomics analysis revealed that the majority of the T. crocea SMPs are novel and dissimilar to known SMPs identified from the other bivalve species. Meanwhile, the SMP repertoire of the crocus clam also includes proteins with conserved functional domains such as chitin-binding domain, VWA domain, and protease inhibitor domain. We also identified BMSP (Blue Mussel Shell Protein, originally reported from Mytilus), which is widely distributed among molluscan shell matrix proteins. Tridacna SMPs also include low-complexity regions (LCRs) that are absent in the other molluscan genomes, indicating that these genes may have evolved in specific lineage. These results highlight the diversity of the organic molecules – in particular proteins – that are essential for molluscan shell formation.

scholarly journals Molluscan Shell Matrix Characterization by Preparative SDS-PAGE

2003 ◽  
Vol 3 ◽  
pp. 342-347 ◽  
Author(s):  
Frederic Marin
Keyword(s):  
Polyclonal Antibody ◽  
Mineral Phase ◽  
Preparative Electrophoresis ◽  
Molluscan Shell ◽  
In Vitro Characterization ◽  
Shell Matrix ◽  
Sds Page ◽  
Shell Proteins

The glycoproteinaceous constituents of molluscan shell matrices usually resist chromatographical fractionation. We describe a protocol that overcomes this difficulty and permits collection of a large amount of shell proteins for further in vitro characterization. After dissolution of the mineral phase, the glycoproteins are fractionated �blind� on a preparative electrophoresis. They are subsequently detected with a polyclonal antibody raised against the whole matrix.

The Possible Calcification Mechanisms in some Reptilian Egg-shells

1959 ◽  
Vol s3-100 (52) ◽  
pp. 529-538
Author(s):  
K. SIMKISS ◽  
C. TYLER
Keyword(s):  
Toluidine Blue ◽  
Organic Matrix ◽  
Acid Mucopolysaccharide ◽  
Amino Group ◽  
Carboxylate Group ◽  
Shell Matrix ◽  
The Matrix ◽  
Egg Shells ◽  
Egg Shell ◽  
Comparison Of The Results

Studies have been made of the organic matrix of certain reptilian egg-shells. The interaction between egg-shell-matrix and various metal ions has been considered by noting the effect of these ions on the staining of the matrix by toluidine blue. A comparison of the results with those for the hen indicates that the chelating mechanism in the Chelonia is similar to that in the hen, but that that in the Crocodilia is different. It is suggested that in the Crocodilia the acid mucopolysaccharide of the matrix is embedded in, but not combined with, the protein and that its chelating mechanism is carboxylate group to carboxylate group, while in the hen and Chelonia, the acid mucopolysaccharide is combined with the protein and that its chelating mechanism is carboxylate group to amino group.

scholarly journals Characterization of the main steps in first shell formation in Mytilus galloprovincialis : possible role of tyrosinase

2019 ◽  
Vol 286 (1916) ◽  
pp. 20192043 ◽  
Author(s):  
A. Miglioli ◽  
R. Dumollard ◽  
T. Balbi ◽  
L. Besnardeau ◽  
L. Canesi
Keyword(s):  
Time Course ◽  
Mytilus Galloprovincialis ◽  
Enzyme Inhibitor ◽  
Organic Matrix ◽  
Mrna Levels ◽  
Shell Formation ◽  
Larval Stages ◽  
Matrix Deposition ◽  
Shell Matrix

Bivalve biomineralization is a highly complex and organized process, involving several molecular components identified in adults and larval stages. However, information is still scarce on the ontogeny of the organic matrix before calcification occurs. In this work, first shell formation was investigated in the mussel Mytilus galloprovincialis . The time course of organic matrix and CaCO 3 deposition were followed at close times post fertilization (24, 26, 29, 32, 48 h) by calcofluor and calcein staining, respectively. Both components showed an exponential trend in growth, with a delay between organic matrix and CaCO 3 deposition. mRNA levels of genes involved in matrix deposition (chitin synthase; tyrosinase- TYR) and calcification (carbonic anhydrase; extrapallial protein) were quantified by qPCR at 24 and 48 hours post fertilization (hpf) with respect to eggs. All transcripts were upregulated across early development, with TYR showing highest mRNA levels from 24 hpf. TYR transcripts were closely associated with matrix deposition as shown by in situ hybridization. The involvement of tyrosinase activity was supported by data obtained with the enzyme inhibitor N-phenylthiourea. Our results underline the pivotal role of shell matrix in driving first CaCO 3 deposition and the importance of tyrosinase in the formation of the first shell in M. galloprovincialis .

Genetic Coding in Biomineralization of Microlaminate Composites

1992 ◽  
Vol 292 ◽  
Author(s):  
Daniel E. Morse ◽  
Marios A. Cariolou ◽  
Galen D. Stucky ◽  
Charlotite M. Zaremba ◽  
Paul K. Hansma
Keyword(s):  
Organic Matrix ◽  
Nucleation And Growth ◽  
Direct Crystallization ◽  
Basic Principles ◽  
Shell Matrix ◽  
Additional Protein ◽  
Flexible Deformation ◽  
Abalone Shell ◽  
Crystalline Domains ◽  
Present Understanding

AbstractBiomineralization is precisely controlled by complex templating relationships ultimately encoded in the genes. In the formation of the molluscan shell, polyanionic pleated sheet proteins serve as templates for the nucleation and epitaxial growth of calcium carbonate crystalline domains to yield microlaminate composites of exceptional strength and crystal ordering. The strength and fracture-resistance of these composites far exceed those of the minerals themselves, as a result of both the capacity for flexible deformation of the organic matrix layers and the retardation of crack propagation at each mineral-organic interface. The basic principles controlling low temperature biosynthesis of these materials thus are of both fundamental and applied importance. The abalone shell consists of microlaminates with a remarkable regularity of lamina thickness (ca. 0.5 micron), the formation of which defies present understanding. We have found that shells of abalone larvae formed prior to metamorphosis contain only aragonite, whereas the adult shell made after metamorphosis contains both aragonite and calcite. This transition is accompanied by a switch in genetic expression of the template proteins, suggesting that the premetamorphic protein may serve as a template for aragonite nucleation and growth, while template proteins synthesized after metamorphosis may direct crystallization of calcite. These analyses are based on improvements we recently reported for the detection and purification of proteins from the demineralized shell matrix. Genetic cloning experiments now in progress are aimed at discovering additional protein sequences responsible for the programmed control of crystal phase termination, since it is the termination and reinitiation of mineralization that is responsible for the regularity of highly ordered microlaminates produced in nature.

Shell matrices of Recent rhynchonelliform brachiopods: microstructures and glycosylation studies

2007 ◽  
Vol 98 (3-4) ◽  
pp. 415-424 ◽  
Author(s):  
Danièle Gaspard ◽  
Frédéric Marin ◽  
Nathalie Guichard ◽  
Sylvain Morel ◽  
Gérard Alcaraz ◽  
...  
Keyword(s):  
Organic Matrix ◽  
Crystal Nucleation ◽  
Low Molecular Weight ◽  
Post Translational Modifications ◽  
Shell Matrix ◽  
Positive Smear ◽  
Pas Staining ◽  
Polysaccharide Composition ◽  
Calcification Process ◽  
Outer Mantle Epithelium

ABSTRACTLike most metazoan biomineralisations, the brachiopod shell is the end product of a biologically controlled calcification process. The main agent of the control is the extracellular matrix, which is secreted by the outer mantle epithelium. This matrix mediates the calcification process by allowing crystal nucleation and elongation in specific orientations and finally, by stopping crystal growth. The proteinaceous moiety of brachiopod shell matrices has been extensively studied. Less known are the post-translational modifications that occur in these matrices, in particular glycosylations. In this comparison of five species of Recent articulated brachiopods, the ratio of soluble to insoluble organic matrix varies between the species. Polydisperse macromolecular materials occur in each of these species with discrete proteins of 50 kDa in Notosaria nigricans, Calloria inconspicua and Neothyris lenticularis, 37 kDa in Terebratulina retusa and Gryphus vitreus and 20–25 kDa in N. nigricans. Protein mixtures from all five species respond differently to anionic stains (Stains-All and Alcian Blue). PAS staining results in a positive smear in C. inconspicua and T. retusa and highlights low molecular weight glycoproteins in C. inconspicua. The polysaccharide composition of the soluble matrix of T. retusa is different from the others due to high proportions of arabinose and low proportions of fucose. In all cases, polysaccharide composition of the insoluble matrix is dominated by glucose and glucosamine. Insoluble matrices have more glucose and xylose and less galactosamine and glucosamine than the corresponding soluble matrix. Relatively high amounts of glucosamine may suggest the presence of chitin in the shell matrix of rhynchonelliform brachiopods.

Chemically- and mechanically-tunable porated polyethylene glycol gels for leukocyte integrin independent and dependent chemotaxis

TECHNOLOGY ◽  
2014 ◽  
Vol 02 (02) ◽  
pp. 133-143 ◽  
Author(s):  
Holly M. Lauridsen ◽  
Bryan J. Walker ◽  
Anjelica L. Gonzalez
Keyword(s):  
Mechanical Properties ◽  
Polyethylene Glycol ◽  
Inflammatory Diseases ◽  
New Technology ◽  
Complex Mixture ◽  
Biochemical Properties ◽  
In Vitro Models ◽  
Leukocyte Migration ◽  
Mechanical Stiffness

The extracellular matrix (ECM) is a highly complex mixture of protein, proteoglycans and growth factors that biochemically and mechanically regulates leukocyte migration during inflammation. Perturbations in ECM composition and mechanical properties are associated with the pathogenesis of chronic inflammatory diseases ranging from asthma to diabetes. The limited availability of in vitro models of human ECM has impeded inflammatory research, as current methods rely heavily on polycarbonate transwells and glass coverslips, which cannot accurately replicate the combined mechanical and biochemical properties of human ECM. Polyethylene glycol (PEG) hydrogels offer a highly tunable substrate, with respect to both mechanical properties (as a function of molecular weight) and protein conjugation; unmodified PEG, however, cannot be used for leukocyte migration studies due to its impenetrable pore networks. We present a modifi ed PEG membrane in which hydrogel pore size, pore density, mechanical stiffness, and protein presentation can be easily controlled to mimic various human ECM, providing a new technology for investigating leukocyte recruitment.

Amino acid residues in conodont elements

2002 ◽  
Vol 76 (3) ◽  
pp. 518-528 ◽  
Author(s):  
A. Kemp
Keyword(s):  
Organic Matter ◽  
Amino Acid ◽  
Amino Acid Content ◽  
Organic Matrix ◽  
Organic Content ◽  
Amino Acid Residues ◽  
Hard Tissues ◽  
Collagen Molecules ◽  
Biochemical Analyses ◽  
Phylogenetic Affinities

Thermally unaltered conodont elements, brachiopods, and vertebrates were analyzed with reverse phase high profile liquid chromatography to locate and quantify amino acid remnants of the original organic matrix in the fossils. No consistent similarities in amino acid content were found in conodont taxa, and criteria based on organic residues appear to have no taxonomic significance in the fossils tested from these localities. However, hydroxyproline, an amino acid that is found in the collagen molecules of animals, as well as in the glycoproteins in the cell walls and reproductive tissues of certain plants, is represented in most taxa. The organic matter retained in the impermeable crowns of conodont elements might have been derived originally from a form of collagen. Biochemical analyses, correlated with histochemical tests, demonstrate that organic matter is an integral part of the hyaline tissue of the element crown and not the result of surface contamination. Tests of a range of vertebrate and invertebrate fossil hard tissues produced similar results. The analyses indicate that hyaline tissue in the conodont element crown is not a form of vertebrate enamel, which contains no collagen. Albid tissue, with little or no organic content, is not a form of vertebrate bone or dentine, both based on collagen and low in mineral. Although these results do not help to determine the phylogenetic affinities of conodont animals, they indicate that conodont elements do not contain hard tissues characteristic of vertebrate animals.

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