Search results for "mollusc"

Shell palaeoproteomics: first application of peptide mass fingerprinting for the rapid identification of mollusc shells in archaeology.

2020

10 pages; International audience; Molluscs were one of the most widely-used natural resources in the past, and their shells are abundant among archaeological findings. However, our knowledge of the variety of shells that were circulating in prehistoric times (and thus their socio-economic and cultural value) is scarce due to the difficulty of achieving taxonomic determination of fragmented and/or worked remains. This study aims to obtain molecular barcodes based on peptide mass fingerprints (PMFs) of intracrystalline proteins, in order to obtain shell identification. Palaeoproteomic applications on shells are challenging, due to low concentration of molluscan proteins and an incomplete unde…

DNA multigene characterization of Fasciola hepatica and Lymnaea neotropica and its fascioliasis transmission capacity in Uruguay, with historical cor…

2017

Background Fascioliasis is a pathogenic disease transmitted by lymnaeid snails and recently emerging in humans, in part due to effects of climate changes, anthropogenic environment modifications, import/export and movements of livestock. South America is the continent presenting more human fascioliasis hyperendemic areas and the highest prevalences and intensities known. These scenarios appear mainly linked to altitude areas in Andean countries, whereas lowland areas of non-Andean countries, such as Uruguay, only show sporadic human cases or outbreaks. A study including DNA marker sequencing of fasciolids and lymnaeids, an experimental study of the life cycle in Uruguay, and a review of hum…

Unveiling the evolution of bivalve nacre proteins by shell proteomics of Unionoidae.

2015

The formation of the molluscan shell nacre is regulated to a large extent by a matrix of extracellular macromolecules that are secreted by the shell forming tissue, the mantle. This so called “calcifying matrix” is a complex mixture of proteins and glycoproteins that is assembled and occluded within the mineral phase during the calcification process. While the importance of the calcifying matrix to shell formation has long been appreciated, the molecular basis that dictates nacre formation remains largely uncharacterized.Recent expressed sequence tag (EST) investigations of the freshwater mussels (Elliptio complanata and Villosa leinosa) provide an opportunity to further characterize the pr…

Skeletal organic matrices in molluscs: origin, evolution, diagenesis

2017

8 pages; International audience; The mollusc shell comprises a small amount of organic macromolecules, mostly proteins and polysaccharides, which, all together, constitute the skeletal organic matrix (SOM). In the recent years, the study of the SOM of about two dozens of mollusc species via transcriptomics and/or proteomics has led to the identification of hundreds of shell-associated proteins. This rapidly growing set of data allows several comparisons, shedding light on similarities and differences at the primary structure level and on some peculiar evolutionary mechanisms that may have affected SOM proteins. In addition, it constitutes a prerequisite for investigating the SOM repertoires…

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

2021

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 hav…

Carbonic anhydrase and metazoan biocalcification: a focus on molluscs.

2015

Carbonic anhydrase is a super-family of metallo-enzymes (containing α, β, γ, ζ and δ-CA families) that catalyse the reversible hydration of carbon dioxide. Among their numerous functions, CAs - in particular that of the α-CA family - are known to play a key role in biocalcification processes, i.e., the ability to deposit calcium carbonate crystallites in a controlled manner to form exoskeletons. In the gastropod mollusc Haliotistuberculata – the European abalone – we identified two CA transcripts, htCA1 and htCA2, in the mantle, the calcifying organ responsible for shell formation from an extracellular organic matrix and a mixture of inorganic ions. Because these two transcripts are specifi…

The shell of the invasive bivalve species Dreissena polymorpha: biochemical, elemental and textural Investigations.

2016

28 pages; International audience; The zebra mussel Dreissena polymorpha is a well-established invasive model organism. Although extensively used in environmental sciences, virtually nothing is known of the molecular process of its shell calcification. By describing the microstructure, geochemistry and biochemistry/proteomics of the shell, the present study aims at promoting this species as a model organism in biomineralization studies, in order to establish a bridge with ecotoxicology, while sketching evolutionary conclusions. The shell of D. polymorpha exhibits the classical crossed-lamellar/complex crossed lamellar combination found in several heterodont bivalves, in addition to an extern…

2019

Global changes promote the spread of infectious diseases worldwide. In this context, tropical urogenital schistosomiasis is now permanently established in Corsica since its first emergence in 2013. The local persistence of the tropical pathogens (schistosomes) responsible for urogenital schistosomiasis at such latitudes might be explained by (i) the presence of its intermediate host, the snail Bulinus truncatus, (ii) the recurrent local reseeding of schistosomes by their vertebrate hosts (either human or animal) every summer, and/or (iii) the maintenance and survival of schistosomes within their snail hosts over winter. In this study we conducted an ecological experiment to assess the abili…

Proteomic analysis of the organic matrix of the abalone Haliotis asinina calcified shell.

2010

Abstract Background The formation of the molluscan shell is regulated to a large extent by a matrix of extracellular macromolecules that are secreted by the shell forming tissue, the mantle. This so called "calcifying matrix" is a complex mixture of proteins and glycoproteins that is assembled and occluded within the mineral phase during the calcification process. While the importance of the calcifying matrix to shell formation has long been appreciated, most of its protein components remain uncharacterised. Results Recent expressed sequence tag (EST) investigations of the mantle tissue from the tropical abalone (Haliotis asinina) provide an opportunity to further characterise the proteins …

Descripción de un nuevo limácido de Menorca (Islas Baleares): Gigantomilax (Vitrinoides) benjaminus sp. n. (Gastropoda, Pulmonata)

2008

We describe a new endemic limacid slug, Gigantomilax (Vitrinoides) benjaminus n. sp. and we compare it with the nearest species, particularly with Gigantomilax (V.) majoricensis, another Balearic endemism. Characteristic features of this new species include its small size, translucid and smooth body, and totally grey dorsum with no bands or spots. The reproductive system shows a well developed vas deferens surrounded by the distal part of prostatic gland, a thin penial retractor muscle, swollen prostate and small distal genitalia. The recent redescription of Limax majoricensis by Wiktor et al. (2007) is discussed and we consider that these authors refer to G. benjaminus n. sp., and so we de…