Changes in the transcriptome of bovine ovarian cortex during follicle activation in vitro
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ABSTRACT:
ORGANISM(S): Bos taurus
PROVIDER: GSE69094 | GEO | 2015/10/31
SECONDARY ACCESSION(S): PRJNA284524
REPOSITORIES: GEO
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Project description:A key transition in ovarian follicular development is the activation of resting primordial follicles to the growing primary follicle stage. The signals that regulate activation are still not well understood, especially in non-rodent species. we combined a microarray approach with an in vitro system to gain insight into the regulation of follicle activation. Genes and pathways identified in this study provide interesting candidates for further investigation of mechanisms underlying follicle activation. Fetal bovine ovarian cortical pieces enriched for primordial or primary follicles were obtained by culture with cotrol medium supplemented with TS+ (transferrin, selenous acid, BSA, and linoleic acid) or with insulin (ITS+), a factor that stimulate bovine follicle activation. Total RNA was extracted. Differences in global gene expression profiles between pieces enriched for primordial or primary follicles were determined by microcarray analysis.
2015-10-31 | E-GEOD-69094 | biostudies-arrayexpress
Project description:The dormant population of ovarian primordial follicles is determined at birth and serves as the reservoir for future female fertility. Of equal importance to fertility is the rate that primordial follicles activate and enter folliculogenesis, yet our understanding of the molecular, biochemical, and cellular processes underpinning primordial follicle activation remains limited. The survival of primordial follicles relies on the correct complement and morphology of granulosa cells, which provide signalling factors essential for oocyte and follicular survival. To investigate the contribution of granulosa cells in the primordial-to-primary follicle transition, ovaries from C57Bl/6 mice were enzymatically dissociated at two time points spanning the initial wave of primordial follicle activation. Post-natal day (PND) 1 ovaries yielded primordial granulosa cells, and PND4 ovaries yielded a mixed population of both primordial and primary granulosa cells. The comparative transcriptome of granulosa cells at these time points was generated via the Illumina NextSeq 500 system which identified 132 significantly differentially expressed transcripts. This transcriptomic dataset confirmed the expression of factors known to be involved in primordial follicle activation belonging to TGF-B and EIF4E signalling pathways, as well as novel factors linked to pathways involved in primordial follicle activation (ZFX, POD1, FRZB). This study highlights the dynamic changes in gene expression of granulosa cells during primordial follicle activation and provides evidence for a renewed focus into the Wnt signalling pathway’s role in primordial follicle activation.
2020-12-10 | GSE162927 | GEO
Project description:Primordial follicles are the first class of follicles formed in the mammalian ovary and are comprised of an oocyte surrounded by a layer of squamous pre-granulosa cells. This developmental class remains in a non-growing state until individual follicles activate to initiate folliculogenesis. What regulates the timing of follicle activation and the upstream signals that govern these processes are major unanswered questions in ovarian biology. This is partly due to the paucity of data on staged follicle cells since isolating and manipulating individual oocytes and somatic cells from early follicle stages are challenging. To date, most studies on isolated primordial follicles have been conducted on cells collected from animal-age- or oocyte size-specific samples, which encompass multiple follicular stages. Here, we report a method for collecting primordial follicles and their associated oocytes and somatic cells from neonatal murine ovaries using liberase, DNase I, and Accutase. This methodology allows for the identification and collection of follicles immediately post-activation enabling unprecedented interrogation of the primordial-to-primary follicle transition. Molecular profiling by single-cell RNA sequencing (scRNA-seq) revealed that processes including organelle disassembly and cadherin binding were enriched in oocytes and somatic cells as they transitioned from primordial to the primary follicle stage. Furthermore, targets including WNT4, TGFβ, FOXO3, and a network of transcription factors were identified in the transitioning oocytes and somatic cells as potential upstream regulators that collectively may drive follicle activation. Taken together, we have developed a more precise characterization and selection method for studying staged-follicle cells, revealing several novel regulators of early folliculogenesis.
2022-06-29 | GSE206681 | GEO
Project description:Granulosa cells mature and die as ovarian follicles enlarge and die (undergo atresia) under the influence of hormones and intrafollicular factors. Later in follicular development, a fluid-filled antrum is formed, a process which is accompanied by a high rate of atresia. These small antral follicles (5 mm or less in diameter in the cow) contain granulosa of 2 different phenotypes, rounded or columnar, whereas follicles larger than 5 mm have the rounded phenotype only. Prior to ovulation, in larger follicles greater than 10 mm in size, the granulosa begin to migrate and differentiate in preparation for oocyte release and formation of the corpus luteum. These two key phases of follicular development were studied by gene expression microarray analysis using a bovine model to dissect the molecular mechanisms underlying these processes. Four groups of bovine ovarian follicles were selected for analysis. Follicle size, type and array number for each group are as follows: small (3-5 mm) healthy rounded (n=5), small healthy columnar (n=5), atretic (n=5) and large healthy (>10 mm; n=4). For each group, the RNA from a single follicle was used to hybridise an array, except for 3 small healthy samples which were pooled from 2 follicles each due to low RNA.
2014-05-20 | E-GEOD-39589 | biostudies-arrayexpress
Project description:The assembly of the developmentally arrested primordial follicle and subsequent transition to the primary follicle are poorly understood processes critical to ovarian biology. Abnormal primordial follicle development can lead to pathologies such as premature ovarian failure. The current study used a genome-wide expression profile to investigate primordial follicle assembly and development. Rat ovaries with predominantly unassembled, primordial, or primary follicles were obtained. RNA from these ovaries was hybridized to rat microarray gene chips, and the gene expression (i.e., ovarian transcriptome) was compared between the developmental stages. Analysis of the ovarian transcriptome demonstrated 148 genes up-regulated and 50 genes down-regulated between the unassembled and primordial follicle stages. Observations demonstrate 80 genes up-regulated and 44 genes down-regulated between the primordial and primary follicle stages. The analysis demonstrated 2332 genes common among the three developmental stages, 146 genes specific for the unassembled follicles, 94 genes specific for the primordial follicles, and 151 genes specific for the primary follicles. Steroidogenic genes are up-regulated between unassembled and primordial follicles, and then many are again down-regulated between primordial and primary follicles. The hormones inhibin and Mullerian inhibitory substance (MIS) display a similar pattern of expression with the highest levels of mRNA in the primordial follicles. Several novel unknown genes that had dramatic changes in expression during primordial follicle development were also identified. Gene families/clusters identified that were up-regulated from unassembled to primordial follicles include growth factors and signal transduction gene clusters, whereas a down-regulated gene family was the synaptonemal complex genes associated with meiosis. Gene families/clusters that were up-regulated between primordial and primary follicles included immune response genes, metabolic enzymes, and proteases, whereas down-regulated gene families include the globulin genes and some steroidogenic genes. The expression of several growth factors changed during primordial follicle development, including vascular endothelial growth factor and insulin-like growth factor II. Elucidation of how these changes in gene expression coordinate primordial follicle assembly and the primordial to primary follicle transition provides a better understanding of these critical biological processes and allows selection of candidate regulatory factors for further investigation. Experiment Overall Design: RNA samples from two control groups (pooled untreated cultured ovaries) are compared to two treated groups (pooled cultured ovaries treated with progesterone)
2008-06-16 | E-GEOD-9300 | biostudies-arrayexpress
Project description:The assembly of the developmentally arrested primordial follicle and subsequent transition to the primary follicle are poorly understood processes critical to ovarian biology. Abnormal primordial follicle development can lead to pathologies such as premature ovarian failure. The current study used a genome-wide expression profile to investigate primordial follicle assembly and development. Rat ovaries with predominantly unassembled, primordial, or primary follicles were obtained. RNA from these ovaries was hybridized to rat microarray gene chips, and the gene expression (i.e., ovarian transcriptome) was compared between the developmental stages. Analysis of the ovarian transcriptome demonstrated 148 genes up-regulated and 50 genes down-regulated between the unassembled and primordial follicle stages. Observations demonstrate 80 genes up-regulated and 44 genes down-regulated between the primordial and primary follicle stages. The analysis demonstrated 2332 genes common among the three developmental stages, 146 genes specific for the unassembled follicles, 94 genes specific for the primordial follicles, and 151 genes specific for the primary follicles. Steroidogenic genes are up-regulated between unassembled and primordial follicles, and then many are again down-regulated between primordial and primary follicles. The hormones inhibin and Mullerian inhibitory substance (MIS) display a similar pattern of expression with the highest levels of mRNA in the primordial follicles. Several novel unknown genes that had dramatic changes in expression during primordial follicle development were also identified. Gene families/clusters identified that were up-regulated from unassembled to primordial follicles include growth factors and signal transduction gene clusters, whereas a down-regulated gene family was the synaptonemal complex genes associated with meiosis. Gene families/clusters that were up-regulated between primordial and primary follicles included immune response genes, metabolic enzymes, and proteases, whereas down-regulated gene families include the globulin genes and some steroidogenic genes. The expression of several growth factors changed during primordial follicle development, including vascular endothelial growth factor and insulin-like growth factor II. Elucidation of how these changes in gene expression coordinate primordial follicle assembly and the primordial to primary follicle transition provides a better understanding of these critical biological processes and allows selection of candidate regulatory factors for further investigation. Keywords: expression analysis, developmental time course, follicle assembly, ovary
2007-10-12 | GSE9300 | GEO
Project description:Explore in vivo ovarian follicle transcriptomics from primordial follicles to the antral stage. Ovarian follicles were isolated from CD-1 mice. Entire ovaries were collected at post-natal day 3 and day 4 to collect primordial follicles. Primary follicles (70-90 µm in diameter), two-layered secondary follicles (100-130 µm), multi-layer secondary follicles (150‒180 µm), and pre-antral follicles (200‒300 µm) were mechanically isolated from post-natal day 10, 12, 16, and 18 ovaries, respectively. Antral follicles (400‒600 µm) were mechanically isolated from pregnant mare serum gonadotropin (PMSG)-treated mice ovaries at post-natal day 20. Follicles were then aspirated and combined per ovarian follicle maturation stage (e.g., primary, two-layered secondary). Three different samples were collected from each pooled follicular stage for transcriptomic analysis. RNA was purified and hybridized in MouseRef-8 v2.0 Expression BeadChip Kit (Illumina, San Diego, CA), as previously described (Skory, Bernabe et al., 2013).
2017-04-18 | GSE97902 | GEO
Project description:The activation of dormant primordial follicles is a promising method for rescuing the infertility of aged women and premature ovarian insufficiency (POI) patients. Accumulating evidences in both human and animal suggest that human platelet-rich plasma (hPRP) has the ability to recover ovarian function and promote follicle growth, however the underlying mechanisms remain unclear. In the current study, we revealed that hPRP promoted the activation of primordial follicles and the proliferation of granulosa cells. hPRP treatments significantly increased the levels of phosphorylated protein kinase B (Akt) and forkhead Box O3a (FOXO3a), and the number of oocytes with FOXO3a nuclear export. The hPRP-induced primordial follicle activation could be blocked by LY294002, the inhibitor of PI3K/Akt. By in vivo injection newborn mice model and in vitro culture human ovarian fragments, hPRP was further proved to be effective in the activation of primordial follicles. Taken together, our results suggest that hPRP can promote the primordial follicle activation through the PI3K/Akt pathway. Our results provide a theoretical basis for the clinical application of hPRP in aged women and POI patients.
2024-09-01 | GSE263743 | GEO
Project description:Primordial follicle assembly is a process that occurs in the embryonic or early post natal ovary in which oocyte nests break down to form individual primordial follicles. The size of this initial pool of primordial follicles in part determines the reproductive lifespan of the female. Connective tissue growth factor (CTGF) was identified as a potential regulatory candidate for this process in a previous microarray analysis of follicle development. The current study examines the effects of CTGF and associated transforming growth factor beta 1 (TGFbeta-1) on follicle assembly. Ovaries were removed from newborn rat pups and placed in an organ culture system for two days to measure the effect of these factors on follicle assembly. In addition, ovaries were cultured and treated for ten days to determine the potential of CTGF and TGFbeta-1 to manipulate the primordial follicle pool size over a longer developmental time period. The ovaries treated with CTGF for two days were found to have an increased proportion of assembled follicles. TGFbeta-1 had no effect on primordial follicle assembly and in combination with CTGF decreased oocyte number in the ovary after two days of culture. Over ten days of treatment only the combined treatment of CTGF and TGFbeta-1 was found to cause an increase in the proportion of assembled follicles. Interestingly, treatment with TGFbeta-1 alone resulted in fewer total oocytes in the ovary and decreased the primordial follicle pool size after ten days of culture. Observations indicate that CTGF alone or in combination with TGFbeta-1 stimulates primordial follicle assembly and TGFbeta-1 can decrease the primordial follicle pool size. CTGF was found to regulate the ovarian transcriptome during primordial follicle assembly and an integrative network of genes was identified. CTGF is one of the first growth factors shown to promote primordial follicle assembly, while TGFbeta-1 is one of the first factors shown to decrease the primordial follicle pool size. These observations suggest the possibility of manipulating primordial follicle pool size and influencing female reproductive lifespan. We used microarrays to determine genes expressed differentially between control and CTGF (connective tissue growth factor) treated P0 ovary RNA samples from 3 control groups are compared to 3 CTGF treated ovary groups
2010-09-16 | E-GEOD-22096 | biostudies-arrayexpress
Project description:Primordial follicle assembly is a process that occurs in the embryonic or early post natal ovary in which oocyte nests break down to form individual primordial follicles. The size of this initial pool of primordial follicles in part determines the reproductive lifespan of the female. Connective tissue growth factor (CTGF) was identified as a potential regulatory candidate for this process in a previous microarray analysis of follicle development. The current study examines the effects of CTGF and associated transforming growth factor beta 1 (TGFbeta-1) on follicle assembly. Ovaries were removed from newborn rat pups and placed in an organ culture system for two days to measure the effect of these factors on follicle assembly. In addition, ovaries were cultured and treated for ten days to determine the potential of CTGF and TGFbeta-1 to manipulate the primordial follicle pool size over a longer developmental time period. The ovaries treated with CTGF for two days were found to have an increased proportion of assembled follicles. TGFbeta-1 had no effect on primordial follicle assembly and in combination with CTGF decreased oocyte number in the ovary after two days of culture. Over ten days of treatment only the combined treatment of CTGF and TGFbeta-1 was found to cause an increase in the proportion of assembled follicles. Interestingly, treatment with TGFbeta-1 alone resulted in fewer total oocytes in the ovary and decreased the primordial follicle pool size after ten days of culture. Observations indicate that CTGF alone or in combination with TGFbeta-1 stimulates primordial follicle assembly and TGFbeta-1 can decrease the primordial follicle pool size. CTGF was found to regulate the ovarian transcriptome during primordial follicle assembly and an integrative network of genes was identified. CTGF is one of the first growth factors shown to promote primordial follicle assembly, while TGFbeta-1 is one of the first factors shown to decrease the primordial follicle pool size. These observations suggest the possibility of manipulating primordial follicle pool size and influencing female reproductive lifespan. We used microarrays to determine genes expressed differentially between control and CTGF (connective tissue growth factor) treated P0 ovary
2010-09-16 | GSE22096 | GEO