Project description:We aimed to quantify in silico the expression level of candidate genes in different Clytia gonad tissues and oocytes at different growth stage
Project description:Gene expression profiling was performed by next generation sequencing strategy to explore the transcriptional changes of Papilio clytia and Atrophaneura mencius larvae in response to LPS challenge
Project description: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. 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.
Project description:Proteomics sequence of ricefield eel gonads at five different development stages, the ovary (OV), early intersexual stage gonad (IE), middle intersexual stage gonad (IM), late intersexual stage gonad (IL), and testis (TE).
Project description:Foxl2 is a forkhead transcription factor essential for proper reproductive function in females. It is expressed in the somatic cell population of the gonad (granulosa cells) which forms the follicles of the ovary, the structures responsible for embedding and nurturing the oocytes during their development. FOXL2 directly regulate the aromatase that synthesizes estrogens CYP19A1, thus promoting female differentiation, as well as acting as a repressor of the male factors SOX9 and DMRT1.Expression is also found in the eyelids, pituitary gland and uterus. In the goat, frog and many fish species FOXL2 is a sex-determining gene which, when deleted, leads to female-to-male sex reversal.
Project description:Growing mammalian oocytes accumulate substantial amounts of RNA, most of which are degraded during the subsequent maturation stage. The growth-to-maturation transition begins with germinal vesicle breakdown (GVBD, envisioned as nuclear envelope breakdown) and is critical for oocyte quality. However, the concomitant changes in the transcriptome during GVBD as well as the underlying machinery remained unclear. Here, we report that an RNA exosome-associated RNase, EXOSC10, sculpts the transcriptome at multiple level to facilitate the oocyte growth-to-maturation transition. We establish an oocyte-specific knockout of Exosc10 in mice using CRISPR/Cas9 and find female subfertility due to failed GVBD. By performing single oocyte RNA-seq in different ways, we document dysregulated transcriptomes, unsuccessfully processed rRNAs in mutant oocytes, and many up-regulated RNAs that encode proteins important for endomembrane trafficking, meiotic cell cycle and RNA metabolism. EXOSC10-depleted oocytes have impaired endomembrane components including endosome, lysosome, ER and Golgi. In addition, CDK1 fails to be activated possibly due to persistent WEE1 activity, which blocked lamina phosphorylation and disassembly in mutant oocytes. Collectively, we propose that EXOSC10 promotes the growth-to-maturation transition in mouse oocytes by degrading mRNAs that encode growth-phase factors and sculpting the transcriptome to support the maturation phase of oogenesis.