Gonad transcriptome analysis of pearl oyster Pinctada margaritifera: identification of potential sex differentiation and sex determining genes
|Author(s)||Teaniniuraitemoana Vaihiti1, Huvet Arnaud2, Levy Peva1, Klopp Christophe3, Lhuillier Emeline4, Gaertner-Mazouni Nabila5, Gueguen Yannick1, Le Moullac Gilles1|
|Affiliation(s)||1 : Ifremer, UMR 241 EIO, Labex CORAIL, BP 7004, 98719 Taravao, Tahiti, Polynésie Française.
2 : IFREMER, UMR 6539, LEMAR, F-29280 Plouzane, France.
3 : INRA, UR875, F-31326 Castanet Tolosan, France.
4 : INRA, GeT PlaGe, F-31326 Castanet Tolosan, France.
5 : Univ Polynesie Francaise, UMR 241, EIO, F-98702 Faaa, Tahiti, France.
|Source||Bmc Genomics (1471-2164) (Biomed Central Ltd), 2014-06 , Vol. 15 , N. 491 , P. 1-20|
|WOS© Times Cited||57|
|Note||Additional file 1: Table S1: Genbank accession numbers of the reference sequences used for sequence analysis. http://www.biomedcentral.com/content/supplementary/1471-2164-15-491-s1.xlsx Additional file 2: Table S2: RNAseq quantification: contig counts. http://www.biomedcentral.com/content/supplementary/1471-2164-15-491-s2.xlsx Additional file 3: Table S3: Primer sequences. http://www.biomedcentral.com/content/supplementary/1471-2164-15-491-s3.xlsx Additional file 4: Table S4: P. margaritifera genes potentially involved in sex determination/differentiation and gametogenesis. http://www.biomedcentral.com/content/supplementary/1471-2164-15-491-s4.xlsx Additional file 5: Table S5: Differentially expressed contigs and their best annotations. http://www.biomedcentral.com/content/supplementary/1471-2164-15-491-s5.xlsx|
|Keyword(s)||Pinctada margaritifera, Gametogenesis, Transcriptome, Differential expression, Sex determinism|
|Abstract||BackgroundBlack pearl farming is based on culture of the blacklip pearl oyster Pinctada margaritifera (Mollusca, lophotrochozoa), a protandrous hermaphrodite species. At first maturation, all individuals are males. The female sex appears progressively from two years old, which represents a limitation for broodstock conditioning for aquaculture production. In marine mollusks displaying hermaphroditic features, data on sexual determinism and differentiation, including the molecular sex determining cascade, are scarce. To increase genomic resources and identify the molecular mechanisms whereby gene expression may act in the sexual dimorphism of P. margaritifera, we performed gonad transcriptome analysis.ResultsThe gonad transcriptome of P. margaritifera was sequenced from several gonadic samples of males and females at different development stages, using a Next-Generation-Sequencing method and RNAseq technology. After Illumina sequencing, assembly and annotation, we obtained 70,147 contigs of which 62.2% shared homologies with existing protein sequences, and 9% showed functional annotation with Gene Ontology terms. Differential expression analysis identified 1,993 differentially expressed contigs between the different categories of gonads. Clustering methods of samples revealed that the sex explained most of the variation in gonad gene expression. K-means clustering of differentially expressed contigs showed 815 and 574 contigs were more expressed in male and female gonads, respectively. The analysis of these contigs revealed the presence of known specific genes coding for proteins involved in sex determinism and/or differentiation, such as dmrt and fem-1 like for males, or foxl2 and vitellogenin for females. The specific gene expression profiles of pmarg-fem1-like, pmarg-dmrt and pmarg-foxl2 in different reproductive stages (undetermined, sexual inversion and regression) suggest that these three genes are potentially involved in the sperm-oocyte switch in P. margaritifera.ConclusionsThe study provides a new transcriptomic tool to study reproduction in hermaphroditic marine mollusks. It identifies sex differentiation and potential sex determining genes in P. margaritifera, a protandrous hermaphrodite species.|