Biomineralization ofSchlumbergerella floresiana, a significant carbonate‐producing benthic foraminifer

Abstract

Most foraminifera that produce a shell are efficient biomineralizers. We analyzed the calcitic shell of the large tropical benthic foraminifer Schlumbergerella floresiana. We found a suite of macromolecules containing many charged and polar amino acids and glycine that are also abundant in biomineralization proteins of other phyla. As neither genomic nor transcriptomic data are available for foraminiferal biomineralization yet, de novo-generated sequences, obtained from organic matrices submitted to ms blast database search, led to the characterization of 156 peptides. Very few homologous proteins were matched in the proteomic database, implying that the peptides are derived from unknown proteins present in the foraminiferal organic matrices. The amino acid distribution of these peptides was queried against the uniprot database and the mollusk uniprot database for comparison. The mollusks compose a well-studied phylum that yield a large variety of biomineralization proteins. These results showed that proteins extracted from S. floresiana shells contained sequences enriched with glycine, alanine, and proline, making a set of residues that provided a signature unique to foraminifera. Three of the de novo peptides exhibited sequence similarities to peptides found in proteins such as pre-collagen-P and a group of P-type ATPases including a calcium-transporting ATPase. Surprisingly, the peptide that was most similar to the collagen-like protein was a glycine-rich peptide reported from the test and spine proteome of sea urchin. The molecules, identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry analyses, included acid-soluble N-glycoproteins with its sugar moieties represented by high-mannose-type glycans and carbohydrates. Describing the nature of the proteins, and associated molecules in the skeletal structure of living foraminifera, can elucidate the biomineralization mechanisms of these major carbonate producers in marine ecosystems. As fossil foraminifera provide important paleoenvironmental and paleoclimatic information, a better understanding of biomineralization in these organisms will have far-reaching impacts.

Reconstructing a Carboniferous inferred coral–alcyonarian association using a biomineralogical approach

“…Besides, Mann () established that the biominerals have some properties which are characteristics regarding their inorganic counterpart (as chemical compositions, crystallography, structures, mechanical properties and so on; as, for instance, in the case of nacre, trilobite calcitic lens or otoliths). These specific properties facilitate the identification of biogenic structures in the fossil record and their comparison with other organisms or biomineralization strategies (Jackson et al ., ; Cuif et al ., ; Sabbatini et al ., ). The present paper summarises the main differences between the biominerals forming the coral wall of Syringopora and those constituting the scales of the epibiont that habited in the waters of Palaeotethys.…”

“…New palaeontological perspectives can be gained from indepth studies of biomineralization in recent and fossil organisms (Lloyd et al, 2008;Raven & Giordano, 2009;Jackson et al, 2010). Comparisons between recent and fossil organisms allow new insights into the formation of skeletal elements through the geological record (Porter, 2010;Cuif et al, 2011;Sabbatini et al, 2014). This knowledge offers an opportunity to establish the systematic affinities of problematical fossils by the study of their biomineralogical features (geochemical signature, crystalline structures and crystallographic properties).…”

Protein Extractions from Amphistegina lessonii: Protocol Development and Optimization

“…Different techniques for breaking the foraminiferal cellular membranes have been previously considered and include mechanically grinding with tweezers or a plastic pestle [ 10 , 11 , 12 , 15 ] and crushing to a fine powder with a mortar and pestle [ 14 ]. All these techniques involve the destruction of the foraminiferal tests.…”

“…This buffer has already been applied to lyse LBFs [ 10 , 11 ]. Other lysis buffers (i.e., 1) 80 mM potassium acetate, 5 mM magnesium acetate, 20 mM Hepes pH 7.5 by Heinz et al [ 12 ], 2) 50 mM Tris-HCl (pH 7.8), 150 mM NaCl, 1% SDS and Complete Mini by Stuhr et al [ 15 ], and 3) 100 mM Tris–HCl (pH 7.4) by Sabbatini et al [ 14 ]) have been previously used on foraminifera. The here-used homemade lysis buffer has been developed over time by one co-author (MB) by modifying the already-existing protein extraction buffer to optimize protein extraction in marine organisms such as mussels, clams, and oysters.…”

“…The investigation of physiological and biochemical changes on foraminifera ascribed to various stressing factors such as heavy metals, organic matter, and thermal pollution (i.e., global climate changes) can provide valuable information on the marine environment’s environmental quality. Unfortunately, to the best of our knowledge, only a few investigations have been performed to characterize the protein content of foraminifera [ 10 , 11 , 12 , 13 , 14 , 15 ]. Doo et al [ 10 ] provided a measurement of the total protein content (i.e., 1.95 ± 0.04 µg/individual) in a foraminiferal species (i.e., Baculogypsina sphaerulata ).…”