Gene Expression in Granulosal Cells From Persistent Follicles

ABSTRACT: Granulosa cells form highly specialized membrane connections with the oocyte and each other, allowing the passage of regulatory molecules and metabolites between cells. These connections must be maintained for oocyte growth in vitro and have been implicated in oocyte aging both in vivo and in vitro. Changes in gene expression in granulosa cells from persistent follicles may adversely affect oocyte development. Previous studies have reported changes in gene expression in oocytes and high embryonic loss associated with persistent follicles. Cows were assigned randomly to two groups; growing follicles on day 8 (young cells) and persistent follicles on day 15 (aged cells) of the estrous cycle (estrus = d 0). Cows were super-stimulated with Folltropin-V® on day 1 to 4 and received 25 mg PGF2α on day 6. Cows in P15 group received progesterone from CIDR-B devices on day 4 through 13. Follicles were aspirated immediately after colpotomy. Granulosa cells were collected from each aspirate, pelleted, and stored at -80° until total RNA isolation. Three biological replicates, after linear amplification, were used in a direct comparison microarray experiment using a bovine oligo array. Microarray data were analyzed using GenePix AutoProcessor (GPAP 3.2; http://darwin.biochem.okstate.edu/gpap32/). The analysis revealed up regulation of 272 genes (M-value ≥ 0.9, q ≤ 0.05) and down regulation of 203 genes (M-value ≤ -0.9, q ≤ 0.05) in granulosa cells from persistent follicles (aged cells) in comparison to growing follicles (young cells). Grouping of these genes into themes revealed down regulation of many genes involved in protein metabolism, amino acid transport, and mitosis regulation and an up-regulation of apoptotic genes. However, there was no change in the expression of gap junction genes. These data suggest that aged cells have a reduced capacity to regulate mitosis and provide amino acids to the oocyte. Supported by project Hatch 427 (NE 1007) of the WV Agricultural and Forestry Experiment Station. This experiment employed a direct comparison between day 8 and day 15 granulosa cells. There are two technical replicates per slide and a total of 5 biological replicates were used for each sample (5 from day 8 and 5 from day 15). Three day 8 samples were labeled with Cy3 and two with Cy5. Two day 15 samples were labeled with Cy3 and three samples with Cy5.

ORGANISM(S): Bos taurus

SUBMITTER: Jianbo Yao 

PROVIDER: E-GEOD-4930 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress