Identification of discriminant genes and gene networks involved in pig ovarian follicular atresia
ID:
状态:
发布时间June 24, 2010
, 更新时间 June 10, 2011
, 提交时间 April 25, 2007,
物种:
Sus scrofa
摘要:
Folliculogenesis corresponds to the development of follicles leading to either ovulation or degeneration (a process called atresia). Even if atresia involves an apoptosis process, this mechanism is not well understood. The objective of this experiment was : 1) to analyse gene expression in pig granulosa cells of ovarian follicles during atresia using transcriptome analysis with a 9 024 cDNAs microarray, 2) the identification of gene networks involved in pig ovarian follicular atresia. Granulosa cells were isolated from atretic follicles (small, medium or large). Gene expression was analysed by hybridization of nylon cDNA microarrays. The images were quantified using Bzscan software and the data were managed with BASE software. Statistical analysis was performed using R software. Keywords: pig ovary, folliculogenesis, atresia, gene expression, cDNA microarray, bio-analysis Calibrated follicles were isolated from porcine ovaries after ovariectomy (24h ou 96h after the end of progestagen treatment: Regumate 18 days, 20 mg/days). The follicular status was determined by histological criteria using Feulgen coloration (Monget et al. 1993, Besnard et al. 1996). Healthy follicle is characterized by frequent mitosis and pyknosis absence in granulosa cells. Presence of frequent pyknotic bodies in granulosa cells and no mitosis were allocated to atretic cells. Two cross-classified biological factors of pig ovarian follicles are considered : 1) the stage of development of the follicular growth : small (1-2 mm of diameter), medium (3 mm) and large (>5 mm) follicles; 2) the follicular status: healthy (S1) vs beginning (A2) or advanced (A3) atresia. Gene expression was analysed by hybridization of nylon cDNA microarrays (GPL3729). After hybridisation the data analysis using BASE software and statistical analysis was performed to identify regulated genes. For each of three follicle class and three follicle status combination 4 biological replicates were considered. Total 36 membranes were first hybridized with a vector oligonucleotide labeled (T7 probe 5'-taatacgactcactataggga-3') with gamma33P ATP at 42°C during 12h to determine the quality of the spotting process. After being washed, the arrays were exposed 6 or 24 hours to radioisotopic-sensitive imaging plates (BAS-2025, Fujifilm, Raytest France S.A.R.L., Courbevoie, France). The imaging plates were scanned thereafter with a phosphor imaging system at a 25 µm resolution (BAS-5000, Fujifilm, Raytest France S.A.R.L., Courbevoie, France). Data were acquired with help of a microarray image processing software - AGScan (Cathelin, 2006,