Changes in granulosa cells' gene expression associated with increased oocyte competence in bovine

Abstract

One of the challenges in mammalian reproduction is to understand the basic physiology of oocyte quality. It is believed that the follicle status is linked to developmental competence of the enclosed oocyte. To explore the link between follicles and competence in cows, previous research at our laboratory has developed an ovarian stimulation protocol that increases and then decreases oocyte quality according to the timing of oocyte recovery post-FSH withdrawal (coasting). Using this protocol, we have obtained the granulosa cells associated with oocytes of different qualities at selected times of coasting. Transcriptome analysis was done with Embryogene microarray slides and validation was performed by real-time PCR. Results show that the major changes in gene expression occurred from 20 to 44 h of coasting, when oocyte quality increases. Secondly, among upregulated genes (20-44 h), 25% were extracellular molecules, highlighting potential granulosa signaling cascades. Principal component analysis identified two patterns: one resembling the competence profile and another associated with follicle growth and atresia. Additionally, three major functional changes were identified: i) the end of follicle growth (BMPR1B, IGF2, and RELN), involving interactions with the extracellular matrix (TFPI2); angiogenesis (NRP1), including early hypoxia, and potentially oxidative stress (GFPT2, TF, and VNN1) and ii) apoptosis (KCNJ8) followed by iii) inflammation (ANKRD1). This unique window of analysis indicates a progressive hypoxia during coasting mixed with an increase in apoptosis and inflammation. Potential signaling pathways leading to competence have been identified and will require downstream testing. This preliminary analysis supports the potential role of the follicular differentiation in oocyte quality both during competence increase and decrease phases.Reproduction (2013) 145 555-565

Transcriptomic analysis of cyclic AMP response in bovine cumulus cells

“…We compared the expression patterns of our differentially expressed genes with previously published data (36). In fact, Nivet et al (36) showed the gene expression patterns of granulosa cells that contained oocytes with better developmental potentials. Our data analysis indicates that FID induced expression of 81 genes, which is similar to Nivet et al in cumulus cells (Supplementary Table S1).…”

Transcriptome meta-analysis of three follicular compartments and its correlation with ovarian follicle maturity and oocyte developmental competence in cows

“…All datasets were generated using the EmbryoGENE bovine transcriptome microarray (24). Each experiment focused on a specific cell-type within the ovarian follicle: granulosa cells (21), cumulus cells (5), and the GVBD oocyte (18). Each cell type was analyzed at 20, 44, 68, and 92 h of FSH coasting after ovarian superstimulation with this hormone.…”

“…We subsequently analyzed the effect of FSH coasting for 20, 44, 68, and 92 h on the transcriptomic profiles of granulosa cells (21), cumulus cells (5) and germinal-vesicle breakdown (GVBD) oocytes (18) using same technological platform. In the present study, we performed a meta-analysis of our previous studies in an attempt to identify one or more gene networks active in all three follicular compartments and correlated with FSH coasting time and acquisition of oocyte developmental competence.…”

Application of integrative genomics and systems biology to conventional and in vitro reproductive traits in cattle

“…The literature provides a complex picture of the molecules associated with oocyte competence at different molecular level: proteomics, transcriptomics (Jiang et al, 2010;Gilbert et al, 2012;Nivet et al, 2013) and metabolomics (Matoba et al, 2014). Furthermore, numerous studies focused on the characterization of the expression profiles of granulosa cells from follicles at different developmental stages (Hatzirodos et al, 2014b;Girard et al, 2015) and physiological condition (Hatzirodos et al, 2014a).…”