In vivo gene expression in granulosa cells during pig terminal follicular development

Abstract

Ovarian antral follicular development is clearly dependent on pituitary gonadotrophins FSH and LH. Although the endocrine mechanism that controls ovarian folliculogenesis leading to ovulation is quite well understood, the detailed mechanisms and molecular determinants in the different follicular compartments remain to be clarified. The aim of this study was to identify the genes differentially expressed in pig granulosa cells along the terminal ovarian follicle growth, to gain a comprehensive view of these molecular mechanisms. First, we developed a specific micro-array using cDNAs from suppression subtractive hybridization libraries (345 contigs) obtained by comparison of three follicle size classes: small, medium and large antral healthy follicles. In a second step, a transcriptomic analysis using cDNA probes from these three follicle classes identified 79 differentially expressed transcripts along the terminal follicular growth and 26 predictive genes of size classes. The differential expression of 18 genes has been controlled using real-time PCR experiments validating the micro-array analysis. Finally, the integration of the data using Ingenuity Pathways Analysis identified five gene networks providing descriptive elements of the terminal follicular development. Specifically, we observed: (1) the down-expression of ribosomal protein genes, (2) the genes involved in lipid metabolism and (3) the down-expression of cell morphology and ion-binding genes. In conclusion, this study gives new insight into the gene expression during pig terminal follicular growth in vivo and suggested, in particular, a morphological change in pig granulosa cells accompanying terminal follicular growth. Reproduction (2008) 136 211-224

A small set of extra-embryonic genes defines a new landmark for bovine embryo staging

“…A pre-filtering of 2000 EST (Dudoit & Fridlyand 2002) was carried out with an F test at P value !0.1. RFs (Breiman 2001): a stabilised version of RF (Bonnet et al 2008) was applied by combining several RFs. RF outputs an important measurement of all variables based on the way each tree in the forest is constructed and how important is the role of the variables splitting each node of the tree to infer a good classification of the samples (mean decrease Gini measure).…”

Transcriptome Profiling of Granulosa and Theca Cells During Dominant Follicle Development in the Horse1

“…The growth and maturation of a dominant follicle and subsequent follicle-luteal transition involve sequential and profound changes in tissue structure and function requiring finely tuned and coordinated changes in gene expression at each developmental step. Hundreds of genes involved in follicle selection (i.e., differentially expressed between early dominant [ED] and subordinate follicles) or in ovulation and the associated follicle-luteal transition have been identified by transcriptome profiling of ruminant [2][3][4][5][6], pig [7,8], and primate [9,10] tissues, often using either whole follicles or granulosa cells (GCs). Comparatively more limited information exists in relation to the development of the dominant follicle between the time of selection and the preovulatory (PO) period, particularly in relation to each separate follicular wall cell component, i.e., GCs and theca cells (TCs).…”

A pilot study on transcriptome data analysis of folliculogenesis in pigs

“…The top genes hold useful information concerning their discrimination properties, as shown in Figure 4. APEX_CAVPO (NPTX2), VIIC2 (RPLPO), RS5_HUMAN.1 (RPS5), GPX (GPX3) and calpaïn (CAPNS1) are all down-regulated in L while the clone X3846497.1.ss.5 (NR5A2) is up-regulated in L. These boxplots also show that there is no clear discrimination that can be made between S and M. The regulation of these six genes has been investigated by real-time quantitative PCR and all the regulations were confirmed (Bonnet et al, 2008b) and personal communication.…”