Project description:Well balanced and timed energy metabolism is essential for making a high quality egg. However, the metabolic framework that supports oocyte development remains poorly understood. Here we obtained the temporal metabolome profiles of mouse oocytes during in vivo maturation by isolating large number of cells at key stages. In parallel, quantitative proteomic analyses were conducted to bolster the metabolomic data, synergistically depicting the global metabolic patterns in oocytes. In particular, we discovered novel metabolic features during oocyte maturation, such as the fall in polyunsaturated fatty acids (PUFAs) level and the active serine-glycine-one-carbon (SGOC) pathway. Using functional approaches, we further identified two key targets (NKAP and BTG4) through which arachidonic acid (ARA) inhibits meiotic maturation, and demonstrated the control of epigenetic marks in maturing oocytes by SGOC network. Our data serves as a broad resource on the dynamics occurring in metabolome and proteome during oocyte maturation, and provides opportunities for predicting and improving oocyte quality.
Project description:Well-balanced and timed metabolism is the prerequisite for optimal oocyte development. To date, numerous studies have focused on the utilization of exogenous substrates by oocytes, whereas the underlying mechanism of intrinsic regulation during meiotic maturation is less characterized. Herein, we performed an integrated analysis of parallel metabolomics and transcriptomics by isolating porcine oocytes at three time points, cooperatively depicting the global picture of the metabolic patterns during oocyte maturation. In particular, we identified the metabolic features of porcine oocytes during meiotic maturation, such as the fall in bile acids, the active one-carbon metabolism and a progressive decline in nucleotide metabolism. Collectively, the current study not only provide a comprehensive multiple omics data resource, but also may promote the discovery of biomarkers in the prediction and improvement of oocyte quality.
Project description:Poly(A) polymerase α (PAPα), as the specific mRNA polyadenylation enzyme in the cytoplasm of mammalian oocytes, is essential for oocytes to exclude the first polar body. However, PAPα knockout did not affect germinal vesicles breakdown (GVBD) of oocytes, and the mechanism needs to be further explored. In this study, we identified that PAPα work together with poly(A)-bound RNA binding protein PABPN1 to promote the rupture of germinal vesicles in mammalian oocytes. The protein level of Pabpn1 gradually increases with the meiotic maturation of oocytes. The oocytes specifically knocked out Pabpn1 at the primary follicle stage could develop into the fully grown (FGO) stage, but hardly could enter into the meiotic process. The activated form of CDK1 was injected into Pabpn1-null oocytes, the oocytes could enter into meiotic process. The translational activity of Pabpn1-null oocytes was significantly lower than that of wild-type oocytes during meiosis. In particular, the expression level of protein (BTG4 and CDC25), which were essential for the meiotic maturation of oocytes, were significantly decreased. Therefore, during the oocyte meiosis process, PABPN1 and PAPα jointly promote the oocyte to enter the meiosis process.
Project description:Well-balanced and timed metabolism is essential for making a high-quality egg. However, the metabolic framework that supports oocyte development remains poorly understood. Here, we obtained the temporal metabolome profiles of mouse oocytes during in vivo maturation by isolating large number of cells at key stages. In parallel, quantitative proteomic analyses were conducted to bolster the metabolomic data, synergistically depicting the global metabolic patterns in oocytes. In particular, we discovered the metabolic features during meiotic maturation, such as the fall in polyunsaturated fatty acids (PUFAs) level and the active serine-glycine-one-carbon (SGOC) pathway. Using functional approaches, we further identified the key targets mediating the action of PUFA arachidonic acid (ARA) on meiotic maturation and demonstrated the control of epigenetic marks in maturing oocytes by SGOC network. Our data serve as a broad resource on the dynamics occurring in metabolome and proteome during oocyte maturation.
Project description:Fully grown oocytes remain transcriptionally quiescent, yet many maternal mRNAs are synthesized and retained in growing oocytes. We now know that maternal mRNAs are stored in a structure called the mitochondria associated ribonucleoprotein domain (MARDO). But the components and functions of MARDO remain elusive. Here, we found that LSM14B knockout prevents the proper storage and timely clearance of mRNAs (including Cyclin B1, Btg4, and other mRNAs that are translationally activated during meiotic maturation), specifically by disrupting MARDO assembly during oocyte growth and meiotic maturation. With decreased levels of storage and clearance, the LSM14B knockout oocytes failed to enter meiosis II, ultimately resulting in female infertility. Our results demonstrate the function of LSM14B in MARDO assembly, couple the MARDO with mRNA clearance and oocyte meiotic maturation
Project description:Oocyte maturation refers to oocytes at the germinal vesicle stage progressing into metaphase II (MII) stage of development. Even though numerous studies have shown key genes and potential important signalling cascades, which drive the GV to MII transition, a system-wide analysis of underlying differences at gene level and especially at transcript level between the two developmental stages of the oocyte is still lacking. For this, we profiled and analysed RNA from pig oocytes across meiotic maturation (GV, MII and damaged, n=15). We detected 22,516 genes for each sample across meiotic maturation. Principal Component analysis of the data clustered the samples in three stages of development (GV, MII and damaged). Differential expression of genes between the three stages will then be used to delineate the pathways which are up-/down-regulated during these developmental stages. Besides, differential transcript usage will be used to identify the difference of oocytes at distinct developmental stages at isoform level, which might be ignored by traditional differential gene expression analysis.
Project description:Fully grown oocytes remain transcriptionally quiescent, yet many maternal mRNAs are synthesized and retained in growing oocytes. We now know that maternal mRNAs are stored in a structure called the mitochondria associated ribonucleoprotein domain (MARDO). But the components and functions of MARDO remain elusive. Here, we found that LSM14B knockout prevents the proper storage and timely clearance of mRNAs (including Cyclin B1, Btg4, and other mRNAs that are translationally activated during meiotic maturation), specifically by disrupting MARDO assembly during oocyte growth and meiotic maturation. With decreased levels of storage and clearance, the LSM14B knockout oocytes failed to enter meiosis II, ultimately resulting in female infertility. Our results demonstrate the function of LSM14B in MARDO assembly, couple the MARDO with mRNA clearance and oocyte meiotic maturation.
Project description:Well-balanced and orderly metabolism is a crucial prerequisite for promoting oogenesis. Involvement of single metabolites in oocyte development has been widely reported; however, the comprehensive metabolic framework controlling oocyte maturation is still lacking. In the present study, we employed an integrated temporal metabolomic and transcriptomic method to analyze metabolism in goat oocytes at key stages, revealing the global picture of the metabolic patterns during maturation. In particular, several significantly altered metabolic pathways during goat oocyte meiosis have been identified, including active serine metabolism, increased utilization of tryptophan, and marked accumulation of purine nucleotide. In summary, the current study not only provides multiple omics data resources for goat oocyte development, but also presents a novel perspective to understand the mechanisms regulating mammalian oogenesis.
Project description:The mechanisms of oocyte meiotic defects and low competence during ovarian aging remains elusive for decades. Using Hi-C (genome-wide chromatin conformation capture) and Smart RNA-seq of oocytes from 6- weeks or 10- months aged ovaries, the abnormal loose chromatin structures and disturbing expression of meiosis associated genes at metaphase I phase were disclosed. Furthermore, the transcriptomic landscape of granulosa cells (GCs) surrounding oocytes from young and aged ovaries reveled that oocyte meiotic maturation was accompanied with a robust increased expression of genes involved with the mevalonate (MVA) pathway in GCs from young ovaries but these genes expression was not upregulated to counterpart level in GCs from aged ovaries.The inhibitor of MVA pathway of GCs, Statins significantly decreased polar body extrusion rate and increased the rate of irregularly assembled spindles and misaligned chromosomes remarkably in oocytes of culumus-oocyte complex (COCs) from young ovaries . Correspondingly, the activitor of MVA pathway of GCs, Geranylgeraniol ameliorated ovarian reserve and reduced meiotic defects in oocytes of COCs from aged ovaries. Mechanistically, MVA pathway activation in GCs culminated oocyte meiotic maturation by upregulating EGF signaling via LH receptor on GCs surrounding oocytes. Together, MVA pathway is a promising therapeutic target for prompting quality of oocytes from aged ovaries.
Project description:In this study we investigated the protein expression patterns during human oocyte in vitro and in vivo maturation (IVO) by single-cell quantitative proteomic analysis of 36 human oocytes. Among 2,094 proteins quantified in 34 oocytes (GV: 11 oocytes, IVM: 12 oocytes, IVO: 11 oocytes), 224 were differential between IVO and GV oocytes during in vivo maturation, and 61 between IVM and IVO oocytes.