@article {4419, title = {GigaTON: an extensive publicly searchable database providing a new reference transcriptome in the pacific oyster Crassostrea gigas.}, journal = {BMC Bioinformatics}, volume = {16}, year = {2015}, month = {2015}, pages = {401}, abstract = {

BACKGROUND: The Pacific oyster, Crassostrea gigas, is one of the most important aquaculture shellfish resources worldwide. Important efforts have been undertaken towards a better knowledge of its genome and transcriptome, which makes now C. gigas becoming a model organism among lophotrochozoans, the under-described sister clade of ecdysozoans within protostomes. These massive sequencing efforts offer the opportunity to assemble gene expression data and make such resource accessible and exploitable for the scientific community. Therefore, we undertook this assembly into an up-to-date publicly available transcriptome database: the GigaTON (Gigas TranscriptOme pipeliNe) database.

DESCRIPTION: We assembled 2204 million sequences obtained from 114 publicly available RNA-seq libraries that were realized using all embryo-larval development stages, adult organs, different environmental stressors including heavy metals, temperature, salinity and exposure to air, which were mostly performed as part of the Crassostrea gigas genome project. This data was analyzed in silico and resulted into 56621 newly assembled contigs that were deposited into a publicly available database, the GigaTON database. This database also provides powerful and user-friendly request tools to browse and retrieve information about annotation, expression level, UTRs, splice and polymorphism, and gene ontology associated to all the contigs into each, and between all libraries.

CONCLUSIONS: The GigaTON database provides a convenient, potent and versatile interface to browse, retrieve, confront and compare massive transcriptomic information in an extensive range of conditions, tissues and developmental stages in Crassostrea gigas. To our knowledge, the GigaTON database constitutes the most extensive transcriptomic database to date in marine invertebrates, thereby a new reference transcriptome in the oyster, a highly valuable resource to physiologists and evolutionary biologists.

}, keywords = {Animals, Base Sequence, Computational Biology, Crassostrea, Databases, Genetic, Gene Library, Gene Ontology, Genome, High-Throughput Nucleotide Sequencing, Molecular Sequence Data, Sequence Analysis, RNA, Software, Transcriptome}, issn = {1471-2105}, doi = {10.1186/s12859-015-0833-4}, author = {Guillaume Rivi{\`e}re and Klopp, Christophe and Ibouniyamine, Nabihoudine and Huvet, Arnaud and Boudry, Pierre and Pascal Favrel} } @article {3591, title = {Biomineralization of Schlumbergerella floresiana, a significant carbonate-producing benthic foraminifer.}, journal = {Geobiology}, volume = {12}, year = {2014}, month = {2014 Jul}, pages = {289-307}, 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.

}, keywords = {Amino Acid Sequence, Amino Acids, Calcification, Physiologic, Carbonates, Electrophoresis, Polyacrylamide Gel, Foraminifera, Molecular Sequence Data, Monosaccharides}, issn = {1472-4669}, doi = {10.1111/gbi.12085}, author = {Sabbatini, A and Bedouet, L and Marie, A and Bartolini, A and Landemarre, L and Weber, M X and Gusti Ngurah Kade Mahardika, I and Berland, Sophie and Zito, F and V{\'e}nec-Peyr{\'e}, M-T} } @article {3394, title = {The Jumonji gene family in Crassostrea gigas suggests evolutionary conservation of Jmj-C histone demethylases orthologues in the oyster gametogenesis and development.}, journal = {Gene}, volume = {538}, year = {2014}, month = {2014 Mar 15}, pages = {164-75}, abstract = {

Jumonji (Jmj) proteins are histone demethylases, which control the identity of stem cells. Jmj genes were characterized from plants to mammals where they have been implicated in the epigenetic regulation of development. Despite the Pacific oyster Crassostrea gigas representing one of the most important aquaculture resources worldwide, the molecular mechanisms governing the embryogenesis and reproduction of this lophotrochozoan species remain poorly understood. However, annotations in the C. gigas EST library suggested the presence of putative Jumonji genes, raising the question of the conservation of this family of histone demethylases in the oyster. Using Primer walking, 5{\textquoteright}-RACE PCR and in silico analyses, we characterized nine Jumonji orthologues in the oyster, called Cg-Jmj, bearing conserved domains critical for putative histone demethylase activity. Phylogenic analyses revealed that oyster Jumonji cluster into two distinct groups: {\textquoteright}single-domain Jmj{\textquoteright} and {\textquoteright}multi-domain Jmj{\textquoteright}, and define 8 subgroups corresponding to each cognate orthologues in metazoans. RT-qPCR investigations showed specific regulations of Cg-Jmj mRNAs during the early development and along the reproduction cycle. Furthermore, in situ and in toto hybridizations indicate that oyster Jumonji genes are transcribed mostly within the gonad in adult oysters whereas they display a ubiquitous expression during embryonic and larval development. Our study demonstrates the presence of nine Jumonji orthologues in the oyster C. gigas. Their domain conservation and their expression profile suggest an implication during reproduction and development, questioning about the epigenetic regulation by histone methylation in lophotrochozoans.

}, keywords = {Animals, Base Sequence, Conserved Sequence, Crassostrea, Evolution, Molecular, Gametogenesis, Gene Expression Regulation, Developmental, Jumonji Domain-Containing Histone Demethylases, Molecular Sequence Data, Multigene Family, RNA, Messenger}, issn = {1879-0038}, doi = {10.1016/j.gene.2013.12.016}, author = {Alexandre Fellous and Pascal Favrel and Guo, Ximing and Guillaume Rivi{\`e}re} } @article {3631, title = {Looking for the bird Kiss: evolutionary scenario in sauropsids.}, journal = {BMC Evol Biol}, volume = {14}, year = {2014}, month = {2014}, pages = {30}, abstract = {

BACKGROUND: The neuropeptide Kiss and its receptor KissR are key-actors in the brain control of reproduction in mammals, where they are responsible for the stimulation of the activity of GnRH neurones. Investigation in other vertebrates revealed up to 3 Kiss and 4 KissR paralogs, originating from the two rounds of whole genome duplication in early vertebrates. In contrast, the absence of Kiss and KissR has been suggested in birds, as no homologs of these genes could be found in current genomic databases. This study aims at addressing the question of the existence, from an evolutionary perspective, of the Kisspeptin system in birds. It provides the first large-scale investigation of the Kisspeptin system in the sauropsid lineage, including ophidian, chelonian, crocodilian, and avian lineages.

RESULTS: Sauropsid Kiss and KissR genes were predicted from multiple genome and transcriptome databases by TBLASTN. Phylogenetic and syntenic analyses were performed to classify predicted sauropsid Kiss and KissR genes and to re-construct the evolutionary scenarios of both gene families across the sauropsid radiation.Genome search, phylogenetic and synteny analyses, demonstrated the presence of two Kiss genes (Kiss1 and Kiss2 types) and of two KissR genes (KissR1 and KissR4 types) in the sauropsid lineage. These four genes, also present in the mammalian lineage, would have been inherited from their common amniote ancestor. In contrast, synteny analyses supported that the other Kiss and KissR paralogs are missing in sauropsids as in mammals, indicating their absence in the amniote lineage. Among sauropsids, in the avian lineage, we demonstrated the existence of a Kiss2-like gene in three bird genomes. The divergence of these avian Kiss2-like sequences from those of other vertebrates, as well as their absence in the genomes of some other birds, revealed the processes of Kiss2 gene degeneration and loss in the avian lineage.

CONCLUSION: These findings contribute to trace back the evolutionary history of the Kisspeptin system in amniotes and sauropsids, and provide the first molecular evidence of the existence and fate of a Kiss gene in birds.

}, keywords = {Amino Acid Sequence, Animals, Avian Proteins, Biological Evolution, Birds, Humans, Kisspeptins, Molecular Sequence Data, Phylogeny, Receptors, G-Protein-Coupled, Reptiles, Sequence Alignment, Synteny}, issn = {1471-2148}, doi = {10.1186/1471-2148-14-30}, author = {Pasquier, J{\'e}r{\'e}my and Anne-Gaelle Lafont and Karine Rousseau and Qu{\'e}rat, Bruno and Chemineau, Philippe and Sylvie Dufour} }