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Nombre de programmes trouvés : 6203

le (20m6s)

Dr Frédéric Marin - Mollusk shell matrices: unexpected functions in biomineralization

To construct their skeletons, all metazoans secrete a complex array of macromolecules that are supposed to display key-functions in biomineralization, such as crystal nucleation and crystal growth orientation. These macromolecules - generally less than 1% of the skeletal weight - are occluded during skeletal growth and can be retrieved and analyzed by dissolving the mineral phase. They comprise proteins, glycoproteins, peptides, polysaccharides, and sometimes, lipids, pigments and metabolites. They constitute collectively the 'calcifying matrix', from which proteins and glycoproteins are the most studied.  In the last decade, the coupling of high-throughput screening ...
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le (19m35s)

Dr Sophie Berland - Probing the mechanical properties and biochemical defence offered by shell matrix proteins in bivalves

Calcium carbonate is paired up with shell matrix proteins in the suited organo-mineral outer shell in molluscs. Advanced knowledge in the shell proteome is achieved with the development of proteomics providing insights in the biological control of biomineralization at the shell side. Four bivalve species of distant kinship were subjected to proteomics for sequence and function pattern analysis of their retrieved shell matrix proteins. Domains ruling for calcification mechanisms, e.g. carbonic anhydrase, chitin binding and tyrosinase remained common in all the species signing sustained calcifying control proteins. Other shell proteins were fitted ...
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le (19m2s)

Dr Christine Paillard - The Brown Ring disease in clams, a double-edged defense mechanism for shell disease recovery!

Brown Ring disease is caused by Vibrio tapetis, which, by adhering to newly secreted shell matrices, interferes with the biomineralization process. Colonization and alteration of the matrices induce the deposit of conchiolin on the inner surface of the valves, forming a characteristic brown deposit instead of contributing to shell growth. This defense mechanism consists firstly in coating the bacteria within the organic layers of melanized matrices, and secondly in covering the brown deposit with shell layers to achieve complete healing of the shell. This defense phenotype varies greatly depending on, (1) the ...
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le (22m38s)

Dr Robbie Rae - Biological armour used to kill parasites

The co-evolution of parasites and hosts has shaped the immune system. One such ‘arms race’ is between parasitic nematodes and their molluscan hosts. One such species (Phasmarhabditis hermaphrodita) can infect and kill several gastropod species and has been formulated into a biological control agent (Nemaslug®) for farmers and gardeners. In order to defend themselves from P. hermaphrodita infection we have recently found that several snail species encapsulate and kill nematodes by producing unknown cells which fuse them to the inner part of the shell. This is a rapid process occurring over 48 ...
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