Project description:Mammalian oocyte development depends on the temporally controlled translation of maternal transcripts, particularly in the coordination of meiotic and early embryonic development when transcription has ceased. The translation of mRNA is regulated by various RNA-binding proteins. We show that the absence of cytoplasmic polyadenylation element-binding protein 3 (CPEB3) neg-atively affects female reproductive fitness. CPEB3-depleted oocytes undergo meiosis normally but experience early embryonic arrest due to a disrupted transcriptome, leading to aberrant protein expression and the subsequent failure of embryonic transcription initiation. We found that CPEB3 stabilizes a subset of mRNAs with a significantly longer 3’UTR that is enriched in its distal region with cytoplasmic polyadenylation elements. Overall, our results suggest that CPEB3 is an im-portant maternal factor that regulates the stability and translation of a subclass of mRNAs that are essential for the initiation of embryonic transcription and thus for embryonic development.
Project description:Reproductive success begins with a healthy egg (a competent oocyte). An oocyte acquires its developmental competence during oogenesis in preparation for accomplishing the critical developmental transition from completion of meiosis to initiation of early embryogenesis. Here we comprehensively characterised the maternal role of major subunits of Hira (i.e. Hira, Cabin1 and Zscan4) during oocyte-to-embryo transition.
Project description:The objective of this study was to identify the expression profile of miRNAs in porcine oocytes derived from follicles of different sizes using RNA high throughput sequencing technology. Oocytes were aspirated from large (3-6 mm) or small (<2 mm) ovarian follicles and tested for developmental competence and chromatin configurations. Small RNA libraries were constructed from both groups and then sequenced on an Illumina NextSeq500. Oocytes from large follicles showed higher developmental competence and different chromatin configuration compared to small oocyte group. In total, 167 and 162 known miRNAs were detected in large and small oocyte groups, respectively with 153 miRNAs were commonly expressed in both groups. In addition, 155 predicted novel miRNAs were detected and quantified. MiR-205, miR-16, miR-148a-3p, miR-125b, and let-7 family were among the top 10 highly abundantly expressed miRNAs in both oocyte groups. Further analysis showed that 8 miRNAs were differentially expressed (DE) between both groups (>2 fold change) with 4 up- and 4 down-regulated miRNAs in large compared to small oocyte group. Target gene prediction followed by KEGG pathway analysis revealed 46 pathways that were enriched with miRNA-target genes. Oocyte meiosis pathway and signaling pathways including FoxO, PI3K-Akt, TGFβ, and cAMP were predictably targeted by DE miRNAs. These results give more insights into the potential role of miRNAs in controlling oocyte developmental competence.
Project description:This SuperSeries is composed of the following subset Series: GSE36602: Transcriptional profiling of somatic cells differentiation throughout oocyte competence acquisition in rainbow trout ovarian follicles. GSE36603: Transcriptional profiling of somatic cells differentiation throughout oocyte competence acquisition in the xenopus ovarian follicles. GSE36604: Transcriptional profiling of cumulus cells differentiation throughout oocyte competence acquisition in the murine ovarian follicles. GSE36605: Transcriptional profiling of cumulus cells differentiation throughout oocyte competence acquisition in the bovine ovarian follicles. Refer to individual Series
Project description:Gene expression profiles of granulosa cells from rat ovarian follicles by Affymetrix rat whole genome array showed that twelve genes were up-regulated, while one gene down-regulated more than 1.5 folds in the normal developmental competence group compared with those in the poor developmental competence group. Gene ontology classification showed that the up-regulated genes included lysyl oxidase and nerve growth factor receptor associated protein 1, which are important in the regulation of protein-lysine 6-oxidase activity, and in apoptosis induction, respectively. The down-regulated genes included glycoprotein-4-beta galactosyltransferase 2, which is involved in the regulation of extracellular matrix organization and biogenesis. Experiment Overall Design: Immature rats were injected with eCG and 24h thereafter with anti-eCG antibody to induce follicular atresia or with pre-immune serum to stimulate follicle development. A high percentage (30-50%, normal developmental competence, NDC) of oocytes from eCG/pre-immune serum group developed to term after embryo transfer compared to those from eCG/anti-eCG (0%, poor developmental competence, PDC). Gene expression profiles of granulosa cells from the above oocyte-collected follicles were assessed by Affymetrix rat whole genome array.
Project description:<p>The metabolic profile of follicular fluid (FF) has been investigated to look for biomarkers for oocyte quality. Resolvin E1 (RvE1), a potent pro-resolving mediator, was reported to have protective action in cell function. The study aimed to examine the predictive value of RvE1 for oocyte quality and to explore the cellular mechanism of RvE1 in improving oocyte competence. Metabolic profiles of 80 FF samples showed a higher level of RvE1 in group A (blastocysts scored ≥ B3BC and B3CB according to Gardner's blastocyst scoring system, N=36) than that of group B (blastocysts scored < B3BC and B3CB, N=44, P=.0018). The receiver operating characteristic (ROC) curve analysis showed that RvE1 level in FF below 8.96 pg/ml (AUC:0.75; 95%CI: 0.64 – 0.86; P=.00012) could predict poor oocyte quality with specificity of 97.22%, suggesting RvE1 as a potential biomarker to exclude inferior oocytes. Besides, the level of RvE1 was found to be significantly lower in FF than in serum (57.49 to 17.62 pg/ml; P=.0037) and was gradually accumulated in the culture medium of cumulus cells (CCs) during cell culture, which indicated that RvE1 came from both blood exudates and local secretion. The in vitro experiment revealed the cellular mechanism of RvE1 in improving oocyte quality by decreasing the cumulus cell apoptotic rate and increasing cell viability and proliferation. It is the first time that the role of RvE1 in reproduction is explored. In conclusion, RvE1 is valuable as a potential exclusive biomarker for oocyte selection and plays a role in improving oocyte quality.</p>
Project description:Current understanding of oocyte quality and developmental potential maintains that stochastic or epigenetic processes modulate the action of determinants that are laid in the oocyte during oogenesis. These determinants are considered to be rather conserved across mice, leading different strains of mice to be used interchangeably. We challenged this assumption and studied the relationship between oocyte composition and developmental quality in four inbred strains of mice, namely 129Sv, C57Bl/6, C3H/HeN and DBA/2J. These oocytes showed large variability developmental competence and embryo quality irrespective of the developmental stimulus (fertilization, somatic cell nuclear transfer, parthenogenesis). To unravel the molecular basis of the observed phenotypes we applied state-of-the-art proteomics (SILAC LC-MS/MS) combined with transcriptomics (RNA deep sequencing). We quantified 1839 proteins and 20413 transcripts simultaneously in oocytes of all four strains. The proteome and the transcriptome had little correlation with each other, highlighting the importance of proteomic quantifications in embryology. We found that proteins that were most variably expressed between oocytes from different strains mainly relate to oocyte biology, ribosome and RNA biogenesis as well as embryo differentiation and chromatin remodelling. Thus, different strains of mice should not be used interchangeably in biology when tackling questions about oogenesis and early development.