Project description:Cows in Negative Energy Balance (NEB) may preferentially divert nutrients away from reproduction, thereby experiencing a period of anovulatory anestrus, delayed ovulation of large follicles and a condition of impaired fertility. To better understand the changes occurring in these large follicles as a function of time post-partum granulosa cells of preovulatory follicles have been collected at different times: 30, 60, 90 and 120 days after calving . An analysis of the transcriptome was performed using a global bovine oligo-array microarray to map the differences in genes expression and cellular functions that occur in the follicular microenvironment during the progressive recovery from NEB condition in dairy cow Four time points experiment: 30, 60, 90 and 120 days. Granulosa cells from the 30, 60 and 90 days compare to the 120 days (reference). Biological replicates: 3 from each time point. One replicate per array.
Project description:Cows in Negative Energy Balance (NEB) may preferentially divert nutrients away from reproduction, thereby experiencing a period of anovulatory anestrus, delayed ovulation of large follicles and a condition of impaired fertility. To better understand the changes occurring in these large follicles as a function of time post-partum granulosa cells of preovulatory follicles have been collected at different times: 30, 60, 90 and 120 days after calving . An analysis of the transcriptome was performed using a global bovine oligo-array microarray to map the differences in genes expression and cellular functions that occur in the follicular microenvironment during the progressive recovery from NEB condition in dairy cow
Project description:The study aimed to uncover differential expression pattern of regulatory microRNAs in bovine granulosa cells derived from preovulatory dominant and subordinate follicles.
Project description:The objective of the study was to determine how maternal age influences the transcriptome of the dominant follicle during the preovulatory period. We tested the hypotheses that delayed ovulation in aged cows is associated with 1) altered gene expression of granulosa cells of preovulatory follicles (24 h after LH treatment) and 2) decreased synthesis of progesterone by granulosa cells of the preovulatory follicle. Granulosa cells of preovulatory follicles obtained 24 h after LH treatment from aged Hereford cows (19.0 ±2.5 years; n=3) were compared to those from young cows (9.0 ± 0.6 years; n=3) using bovine specific microarrays (EmbryoGENE-EMBV3; GPL13226). Results were confirmed by RT-qPCR. A total of 1340 genes or gene isoforms were expressed differentially (≥2-fold change; p ≤ 0.05) in aged cows vs. young cows (daughters of aged cows). In conclusion, transcriptome analysis of granulosa cells from aged cows revealed a delayed or suboptimal response to the preovulatory LH stimulus, represented by delayed cellular differentiation, luteinization and progesterone synthesis.
Project description:The objective of the study was to determine how maternal age influences the transcriptome of the dominant follicle during the preovulatory period. We tested the hypotheses that delayed ovulation in aged cows is associated with 1) altered gene expression of granulosa cells of preovulatory follicles (24 h after LH treatment) and 2) decreased synthesis of progesterone by granulosa cells of the preovulatory follicle. Granulosa cells of preovulatory follicles obtained 24 h after LH treatment from aged Hereford cows (19.0 ±2.5 years; n=3) were compared to those from young cows (9.0 ± 0.6 years; n=3) using bovine specific microarrays (EmbryoGENE-EMBV3; GPL13226). Results were confirmed by RT-qPCR. A total of 1340 genes or gene isoforms were expressed differentially (â¥2-fold change; p ⤠0.05) in aged cows vs. young cows (daughters of aged cows). In conclusion, transcriptome analysis of granulosa cells from aged cows revealed a delayed or suboptimal response to the preovulatory LH stimulus, represented by delayed cellular differentiation, luteinization and progesterone synthesis. Granulosa cells of the dominant preovulatory follicle 24 h after LH treatment were compared between aged vs.young cows. Three biological replicates (each composed of one aged and one young cow). 3 Three technical replicate (dye swap). One biological or technical replicate per array.
Project description:Bovine granulosa cells harvested from cohort follicles at 1.3 days after wave emergence, and from dominant and subordinate follicles at 2.6 days after wave emergence. Total RNA extracted from granulosa cells of 4 cohort, 4 dominant and 4 subordinate follicles was pooled for generation of each respective SAGE library. Keywords: other
Project description:Bovine granulosa cells harvested from cohort follicles at 1.3 days after wave emergence, and from dominant and subordinate follicles at 2.6 days after wave emergence. Total RNA extracted from granulosa cells of 4 cohort, 4 dominant and 4 subordinate follicles was pooled for generation of each respective SAGE library. Keywords: other
Project description:Determining the spatial and temporal expression of genes involved in the ovulatory pathway is critical for the understanding of the role of each estrogen receptor in the modulation of folliculogenesis and ovulation. Estrogen receptor (ER) b is highly expressed in ovarian granulosa cells and mice lacking ERb (bERKO) are subfertile due to inefficient ovulation. Previous work has focused on isolated granulosa cells or cultured follicles and while informative, provides confounding results due to the heterogeneous cell types present including granulosa, theca and oocytes and exposure to in vitro conditions. Herein, we isolated preovulatory granulosa cells from WT and ERb-null mice using laser capture microdissection to examine the genomic transcriptional response downstream of PMSG (mimicking FSH) and PMSG/hCG (mimicking LH) stimulation. This allows for a direct comparison of in vivo granulosa cells at the same stage of development from both WT and ERb-null ovaries. ERb-null granulosa cells showed altered expression of genes known to be regulated by FSH (Akap12 and Runx2) as well as not previously reported (Arnt2 and Pou5f1) in WT granulosa cells. Our analysis also identified 304 genes not previously associated with ERb in granulosa cells. LH responsive genes including Abcb1b and Fam110c show reduced expression in ERb-null granulosa cells; however novel genes including Rassf2 and Megf10 were also identified as being downstream of LH signaling in granulosa cells. Collectively, our data suggests that granulosa cells from ERb-null ovaries may not be appropriately differentiated and are unable to respond properly to gonadotropin stimulation We used microarray to compare the gene expression profiles of wiltype (WT) and Erb-null (bERKO) preovulatory granulosa cells as they respond to either PMSG or PMSG+hCG treatments. Laser microdissection was used to collect a purified population of granulosa cells only from preovulatory follicles. We chose to compre the response to PMSG or PMSG+hCG of granulosa cells collected from either WT and bERKO preovulatory follicles. We chose to collect cells 48h after mice were treated with PMSG to compare the gene expression profile ot preovulatory granulosa cells. We also studied the response of these cells to LH (or hCG) as we collected cells 4h after mice were treated with hCG (peak of transcriptional response to hCG).
Project description:Ovulation requires sequential molecular events and structural remodeling in the ovarian follicle for the successful release of a mature oocyte capable of being fertilised. Critical to this process is progesterone receptor (PGR), a transcription factor highly yet transiently expressed in granulosa cells of preovulatory follicles. Progesterone receptor knockout (PRKO) mice are anovulatory, with a specific and complete defect in follicle rupture. Therefore, this model was used to examine the critical molecular and biochemical mechanisms necessary for successful ovulation. Although PGR is not expressed in the cumulus cells or oocyte of the preovulatory cumulus oocyte complex (COC), it is well known that the COC responds to the cascade of gene expression changes that occurs in preovulatory granulosa cells. We used microarrays to identify putative ‘ovulation’ genes in preovulatory COCs at a time when PGR expression is maximal in granulosa cells (eCG + 8h hCG) and the preovulatory COC and follicle are undergoing the final changes necessary for successful ovulation.