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Series GSE27955 Query DataSets for GSE27955
Status Public on Dec 01, 2012
Title Gametogenesis in an alternative hermaphrodite mollusk, the Pacific Oyster Crassostrea gigas: a microarray-based analysis identifies stage- and sex-specific genes
Organism Magallana gigas
Experiment type Expression profiling by array
Summary Background
The Pacific oyster Crassostrea gigas (Mollusca, Lophotrochozoa) is an alternative and irregular protandrous hermaphrodite. Little is known about the genetic and phenotypic bases of sex determinism in oysters, and little more about the molecular pathways regulating reproduction. We have recently developed and validated a microarray containing 31,918 oligomers (Dheilly et al., 2011) representing the oyster transcriptome. The application of this microarray to the study of mollusks gametogenesis should provide a better understanding of the key factors involved in sex differentiation and the regulation of oyster reproduction.

Results
Expression of the 31,918 ESTs was studied in gonads of oysters cultured along the French Atlantic coasts over a yearly reproductive cycle. Principal component analysis and hierarchical clustering first showed a significant divergence in gene expression patterns of males and females beginning when gonial mitosis started. Early expressed male-specific genes included bindin and female-specific genes included foxL2, a pancreatic lipase related protein, cd63 and vitellogenin. ANOVA analysis of the data further revealed 2482 genes differentially expressed during the course of males and/or females gametogenesis. The expression of 434 genes could be localized in either germ cells or somatic cells of the gonad by comparing the transcriptome of gonads to the transcriptomes of striped oocytes and somatic tissues. Analysis of the annotated genes revealed conserved molecular mechanisms between mollusks and mammals. Genes involved in chromatin condensation, DNA replication and repair, mitosis and meiosis regulation, transcription, translation and apoptosis were expressed in both male and female gonads. Additional lists of genes more specifically involved in either spermatogenesis (meiotic phase, in spermatozoids and mature sperm formation and in flagella structure and movement) or oogenesis (female sex differentiation, transcriptional regulation, cell cycle regulation and oocytes maturation) were also generated.

Conclusions
Our study provides novel insight into spermatogenesis and oogenesis in an alternative hermaphrodite bivalve, the Pacific oyster C. gigas. We identified genes opening new perspectives for functional studies of the signaling pathways implicated in gonad differentiation and development.
 
Overall design Individual gonad oysters were sampled in 3 sites: site 1 = Locmariaquer (Brittany, France), site 2 = Baie des Veys (Normandy, France), and site 3 = Argenton (Brittany, France). 8 undifferentiated stage 0 gonads from site 1 were processed. 4 individuals from site 1 were processed for each gonad developmental stage and sex: stage 1 male, stage 1 female, stage 2 male, stage 2 female, stage 3 male, and stage 3 female. Pools of stage 3 females were prepared with individuals from site 1 and site 2 for biological validation of the results. Striped gonads from stage 3 females were prepared for prediction of gene expression localization.
 
Contributor(s) Dheilly NM, Lelong C, Huvet A, Boudry P, Favrel P, Riviere G, Kellner K, Dubos MP
Citation(s) 25375782
Submission date Mar 14, 2011
Last update date Jul 02, 2015
Contact name Nolwenn Marie Dheilly
E-mail(s) ndheilly@hotmail.fr
Phone 0625253514
Organization name Universite de caen
Department Biological sciences
Lab PE2M
Street address Esplanade de la Paix
City Caen
ZIP/Postal code 14000
Country France
 
Platforms (1)
GPL11353 Oyster Crassostrea gigas microarray v1
Samples (45)
GSM847345 Pool a of gonads stage 3 females from Baie des Veys
GSM847346 Pool b of gonads stage 3 females from Baie des Veys
GSM847347 Pool c of gonads stage 3 females from Baie des Veys
Relations
BioProject PRJNA137739

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE27955_RAW.tar 201.0 Mb (http)(custom) TAR (of TXT)
Processed data included within Sample table

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