Search results for "Pinna nobilis"
showing 10 items of 15 documents
The duplivincular ligament of recent Pinna Nobilis L., 1758: further evidence for pterineid ancestry of the Pinnoidea
2008
A correct interpretation of ligament ontogeny and structure is essential for establishing phylogenetic relationships among higher taxa in the bivalve superorder Pteriomorphia. Recent research on pteriomorphian ligaments has focused on understanding ligament morphospace (Thomas et al., 2000; Ubukata, 2003) and evolutionary pathways. In this regard, studies of the transition from larval to post-larval and adult ligaments (Malchus, 2004) have been especially fruitful. Members of the pteriomorphian superfamily Pinnoidea live with their tapered anterior end buried to varying degrees in sediment. The fan shell Pinna may be buried up to one third of its length (Templado, 2004) (Fig. 1), and Atrina…
Acidic shell proteins of the Mediterranean fan mussel Pinna nobilis.
2011
43 pages; In molluscs, the shell secretion process is controlled by a set of extracellular macromolecules collectively called the shell matrix. The shell matrix, which is produced by the mantle epithelial cells during mineralization, is predominantly composed of proteins, glycoproteins, acidic polysaccharides, and chitin that precisely regulate the deposition of calcium carbonate outside the mantle cells. In the present paper, we focus on the shell of Pinna nobilis, the giant Mediterranean fan mussel, usually considered as a model for studying molluscan biomineralization processes. P. nobilis exhibits indeed a nacro-prismatic shell, the outer layer of which is constituted of the so-called "…
A new twist on sea silk : the peculiar protein ultrastructure of fan shell and pearl oyster byssus
2018
11 pages; International audience; Numerous mussel species produce byssal threads - tough proteinaceous fibers, which anchor mussels in aquatic habitats. Byssal threads from Mytilus species, which are comprised of modified collagen proteins - have become a veritable archetype for bio-inspired polymers due to their self-healing properties. However, threads from different species are comparatively much less understood. In particular, the byssus of Pinna nobilis comprises thousands of fine fibers utilized by humans for millennia to fashion lightweight golden fabrics known as sea silk. P. nobilis is very different from Mytilus from an ecological, morphological and evolutionary point of view and …
Smaller calcite lattice deformation caused by occluded organic material in coccoliths than in mollusk shell.
2015
7 pages; International audience; The growth and nucleation of biominerals are directed and affected by associated biological molecules. In this paper, we investigate the influence of occluded biomolecules on biogenic calcite from the coccolithophorid Pleurochrysis carterae and from chalk, a rock composed predominantly of fossil coccoliths. We compare the results with data on chalk from the extensively studied mussel Pinna nobilis that served as a control. Using high resolution synchrotron powder X-ray diffraction combined with in situ heating, the influence of organic compounds on the structure of the inorganic phase was probed. Two heating cycles allow us to differentiate the effects of th…
Inorganic/Organic interface in biominerals : unveiling the complex structure of two calcitic biomineral models, the red coral Corallium rubrum and th…
2022
Biominerals are organo-minerals structures produced by living systems. Since the Cambrian, they contribute to the adaptation of living organisms to different environments by fulfilling a variety of combined functions that go along with adapted morphologies. One of the aims of biomineralization is to understand how organisms "sculpt" these complex morphologies, in particular at nano and molecular scales. The aim of this PhD work was to understand the complex relationships between the organic and mineral phases. To this end, I focused my analyses on two calcitic biomineral models: 1) the red coral Corallium rubrum and 2) the prismatic shell of the Mediterranean fan mussel Pinna nobilis. My wo…
Density and distribution patterns of the endangered species Pinna nobilis within the harbour bay of Favignana (Egadi Islands MPA)
2015
The fan shell P. nobilis (Linnaeus, 1758) is the largest marine bivalve in the Mediterranean Sea which acts as ecosystem engineer, offering an adequate substratum to several associated benthic species. P. nobilis is threatened by the reduction and loss of its natural habitat and by increased anthropogenic inputs into coastal waters. The knowledge on the population of this species are scarce, especially as concerns Sicily and its coasts. This study focused on the density of population, spatial distribution, level of burial and orientation of the population of P. nobilis in the harbour area of Favignana island (western coast of Sicily, Italy). The fan shell surveys were carried out by SCUBA d…
Protein-induced, previously unidentified twin form of calcite.
2007
Using single-crystal x-ray diffraction, we found a formerly unknown twin form in calcite crystals grown from solution to which a mollusc shell-derived 17-kDa protein, Caspartin, was added. This intracrystalline protein was extracted from the calcitic prisms of the Pinna nobilis shells. The observed twin form is characterized by the twinning plane of the (108)-type, which is in addition to the known four twin laws of calcite identified during 150 years of investigations. The established twin forms in calcite have twinning planes of the (001)-, (012)-, (104)-, and (018)-types. Our discovery provides additional evidence on the crucial role of biological macromolecules in biomineralization.
Caspartin and calprismin, two proteins of the shell calcitic prisms of the Mediterranean fan mussel Pinna nobilis.
2005
We used the combination of preparative electrophoresis and immunological detection to isolate two new proteins from the shell calcitic prisms of Pinna nobilis, the Mediterranean fan mussel. The amino acid composition of these proteins was determined. Both proteins are soluble, intracrystalline, and acidic. The 38-kDa protein is glycosylated; the 17-kDa one is not. Ala, Asx, Thr, and Pro represent the dominant residues of the 38-kDa protein, named calprismin. An N-terminal sequence was obtained from calprismin. This sequence, which comprises a pattern of 4 cysteine residues, is not related to any known protein. The second protein, named caspartin, exhibits an unusual amino acid composition, …
Nanoscale assembly processes revealed in the nacroprismatic transition zone of Pinna nobilis mollusc shells
2015
Intricate biomineralization processes in molluscs engineer hierarchical structures with meso-, nano-, and atomic architectures that give the final composite material exceptional mechanical strength and optical iridescence on the macroscale. This multiscale biological assembly inspires new synthetic routes to complex materials. Our investigation of the prism-nacre interface reveals nanoscale details governing the onset of nacre formation using high-resolution scanning transmission electron microscopy. A wedge polishing technique provides unprecedented, large-area specimens required to span the entire interface. Within this region, we find a transition from nanofibrillar aggregation to irregu…
Merging models of biomineralisation with concepts of nonclassical crystallisation: is a liquid amorphous precursor involved in the formation of the p…
2012
16 pages; International audience; The calcitic prisms of Pinna nobilis (Pinnidae, Linnaeus 1758) are shown to be perfect examples of a mesocrystalline material. Based on their ultrastructure and on the occurrence of an amorphous transient precursor during the early stages of prism formation, we provide evidence for the pathway of mesocrystallisation proposed by Seto et al. (2012), which proceeds not by self-organized oriented attachment of crystalline nano-bricks but by aggregation of initially amorphous nanogranules which later transform by epitaxial nucleation to a threedimensional array of well aligned nanocrystals. We further fathom the role of a liquid amorphous calcium carbonate in bi…