@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 {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} }