Project description:Coordinated interactions between ovarian granulosa and theca cells are required for female endocrine function and fertility. To elucidate these interactions the regulation of the granulosa and theca cell transcriptomes during bovine antral follicle development were investigated. Granulosa cells and theca cells were isolated from small (<5 mm), medium (5-10 mm), and large (>10 mm) antral bovine follicles. A microarray analysis of 24,000 bovine genes revealed that granulosa cells and theca cells each had gene sets specific to small, medium and large follicle cells. Transcripts regulated (i.e., minimally changed 1.5-fold) during antral follicle development for the granulosa cells involved 446 genes and for theca cells 248 genes. Only 28 regulated genes were common to both granulosa and theca cells. Regulated genes were functionally categorized with a focus on growth factors and cytokines expressed and regulated by the two cell types. Candidate regulatory growth factor proteins mediating both paracrine and autocrine cell-cell interactions include macrophage inflammatory protein (MIP1 beta), teratocarcinoma-derived growth factor 1 (TDGF1), stromal derived growth factor 1 (SDF1; i.e., CXCL12), growth differentiation factor 8 (GDF8), glia maturation factor gamma (GMFG), osteopontin (SPP1), angiopoietin 4 (ANGPT4), and chemokine ligands (CCL 2, 3, 5, and 8). The current study examined granulosa cell and theca cell regulated genes associated with bovine antral follicle development and identified candidate growth factors potentially involved in the regulation of cell-cell interactions required for ovarian function. Experiment Overall Design: Granulosacell RNA samples from three groups of follicles different in size - small, medium, and large (pooled untreated ovaries) are compared between each other. Each group has 2 separate biological replicas; each replica contained pooled RNA from 20-40 ovaries from 6-10 different animals.
Project description:Excessive androgen production is a hallmark of human and bovine ovarian disorders, and our lab has identified a naturally-occurring bovine model with excess follicular fluid androstenedione (A4) without a proportional estrogen increase. Granulosa cell populations from both the control, Low A4 follicles and the abnormal, High A4 follicles were isolated. Total RNA was extracted from those granulosa cells and submitted to the University of Nebraska Medical Center Microarray Core Facility for transcriptome quantification using Affymetrix Bovine GeneChip Gene 1.0 ST Arrays. The orignal Affymetrix .CEL files and the normalized linear expression data are included in this submission.
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.