Project description:We selected NSN and SN GV oocytes based on FBL-GFP localization, and performed transcriptome profiling of single NSN and SN GV oocytes, and MII oocytes in vitro matured from NSN and SN GV oocytes.
Project description:During mammalian oocyte growth, chromatin configuration transition from the nonsurrounded nucleolus (NSN) to surrounded nucleolus (SN) type plays a key role in the regulation of gene expression and in acquisition of meiotic and developmental competence by the oocyte. Nonetheless, the mechanism underlying chromatin configuration maturation in oocytes is poorly understood. Here we show that nucleolar protein DCAF13 is an important component of the ribosomal RNA (rRNA)-processing complex and is essential for oocyte NSN–SN transition in mice. A conditional knockout of Dcaf13 in oocytes led to the arrest of oocyte development in the NSN configuration, follicular atresia, premature ovarian failure, and female sterility. The DCAF13 deficiency resulted in pre-rRNA accumulation in oocytes, whereas the total mRNA level was not altered. Further exploration showed that DCAF13 participated in the 18S rRNA processing in growing oocytes. The lack of 18S rRNA because of DCAF13 deletion caused a ribosome assembly disorder and then reduced global protein synthesis. DCAF13 interacted with a protein of the core box C/D ribonucleoprotein, fibrillarin, i.e., a factor of early pre-rRNA processing. When fibrillarin was knocked down in oocytes from primary follicles, the follicle development was inhibited as well, indicating that an rRNA processing defect in the oocyte indeed stunts chromatin configuration transition and follicle development. Taken together, these results elucidated the in vivo function of novel nucleolar protein DCAF13 in maintaining mammalian oogenesis.
Project description:The cumulus cells (CCs) that envelope antral and ovulated oocytes have been regarded as putative source of non-invasive markers of the oocyte developmental competence and a number of studies have observed a correlation between CCs gene expression, embryo quality and final pregnancy outcome. With the aim of identifying marker transcripts, we isolated CCs from antral mouse oocytes of known developmental incompetence (NSN-CCs) or competence (SN-CCs) and compared their transcriptomes. Total RNA was isolated from cumulus cells derived from oocytes with a SN or NSN chromatin organization.
Project description:The cumulus cells (CCs) that envelope antral and ovulated oocytes have been regarded as putative source of non-invasive markers of the oocyte developmental competence and a number of studies have observed a correlation between CCs gene expression, embryo quality and final pregnancy outcome. With the aim of identifying marker transcripts, we isolated CCs from antral mouse oocytes of known developmental incompetence (NSN-CCs) or competence (SN-CCs) and compared their transcriptomes.
Project description:An on-capillary alkylation micro-reactor (OCAM) was developed for parallel measurement of proteome and metabolome in the same single mouse oocytes, enabling the identification of 1775 protein groups and 107 metabolites. By quantitative proteo-metabolome analysis of single oocytes at germinal vesicle (GV) stage, comprehensive characteristics of the different metabolic patterns of SN (surrounded nucleolus) and NSN (non-surrounded nucleolus) oocytes was revealed.
Project description:Mammalian oogenesis is a complex mechanism entailing the maturation of primordial follicles into preovulatory follicles followed by the release of antral oocytes. In the ovary, the antral compartment consists of two populations of oocytes whose main difference regards the ability to resume meiosis and to develop, after the egg-sperm fusion, until the blastocyst stage. Still inexplicably, the antral oocytes distinguishable as Surrounded Nucleolus (SN; 70% of the antral oocytes population) are able to develop to the blastocyst stage, while those showing a Not Surrounded Nucleolus (NSN) arrest at the two-cell stage.
Project description:Implications for neuroprotection in Parkinson's disease Parkinson’s disease and its characteristic symptoms are thought to arise from the progressive degeneration of specific midbrain dopamine (DA) neurons. In humans, DA neurons of the substantia nigra (SN) and their projections to the striatum show selective vulnerability, while neighboring DA neurons of the ventral tegmental area (VTA) are relatively spared from degeneration. This pattern of cell loss is mimicked in humans, primates, and certain rodents by the neurotoxin MPTP. In this study, we aimed to test the hypothesis that there are factors in the VTA that are potentially neuroprotective against MPTP and that these factors change over time. We have found a differential transcriptional response within the cells of the SN and VTA to sustained exposure to a low dose of MPTP. Specifically, the VTA has increased expression of 148 genes as an early response to MPTP and 113 genes as a late response to MPTP toxicity. This response encompasses many areas of cellular function, including protein regulation (Phf6) and ion/metal regulation (PANK2, Car4). Notably, these responses were largely absent from the cells of the SN. Our data show a clear dynamic response in maintaining the homeostasis and viability of the neurons in the VTA that is lacking in the SN after neurotoxin challenge. We used microarrays to analyze the differential response of the substantia nigra (SN) and ventral tegmental area (VTA) to a chronic low dose of the neurotoxin MPTP. Transgenic hTH-GFP mice were treated with MPTP (4mg/kg) for either 2 or 10 days. Control mice were given an equal volume of saline for 10 days. Dopamine neurons from the substantia nigra and ventral tegmental areas of control and MPTP treated animals were laser captured. The RNA was isolated and processed for microarray hybridization. Each group had three biological replicates, for a total of 18 samples. Three each in the following: Control SN, Control VTA, 2 day MPTP SN, 2 day MPTP VTA, 10 day MPTP SN, 10 day MPTP VTA. Samples were log2 transformed and RMA normalized using Agilent Genespring 10.0 GX.
Project description:One OsTudor-SN mutant, EM1084, carrying E503K point mutation and one associated WT-OsTSN complemented transgenic (pHL8042/EM1084 ) were applied in this study. EM1084 was obtained by TILLING studies (http://www.shigen.nig.ac.jp/rice/oryzabase). The E503K mutation site in EM1084 lies within the SN3 domain, while the EM1084 complemented transgenic plant was complemented with the full-length WT OsTSN gene driven by native OsTSN promoter. This mutation results in affecting storage protein mRNA localization and, in turn, with a strong reduction in grain weight and storage protein accumulation. Transcriptome analysis on the dehulled 10-14 days old developing seeds from wild type, EM1084 and pHL8042/EM1084 indicates that partial loss of Tudor-SN function caused the differential expression of storage protein genes and relevant genes involved in several essential biological processes during rice development.
Project description:The molecular properties of benign melanocytic lesions are poorly understood. Only few studies have been performed on specific nevi subtypes, including common nevocellular nevi (NCN) or Spitz nevi (SN). Genomic alterations in melanoma-associated oncogenes are typically absent in SN. In the present study, mRNA expression of 25 SN and 15 NCN were analyzed. Molecular profiling was done using the RNA NanoString nCounter Gene Expression Platform (No. of genes = 770). Marker discovery was performed with a training set consisting of 7 SN and 7 NCN samples from the same patients, and validation was performed using a second set consisting of 18 SN and 8 NCN samples. Using the training set, 197 differentially expressed genes were identified in SN versus NCN. Of these, 74 genes validated in the validation set (FDR Q value ≤ 0.13). In addition, using Random Forest and LASSO feature selection a molecular signature of SN versus NCN was identified including 15 top-ranked genes. Gene set analysis showed upregulation of gene pathways with increased expression of transcripts related to immunomodulatory, inflammatory and extracellular matrix interactions as well as angiogenesis associated processes in SN. Although the molecular characteristics of malignant melanoma have been studied in detail, the molecular properties of benign melanocytic lesions such as common nevocellular nevi (NCN) and Spitz nevi (SN) remain poorly understood. This limited knowledge hinders a better understanding of atypical and malignant transformation of melanocytes. The present study identified a distinct molecular expression profile in SN compared to NCN, even when lesions were obtained from the same patients. These findings strongly indicate that SN represent a distinct group of melanocytic neoplasms and evolve differentially and not sequentially from NCN.