Luteinization of porcine preovulatory follicles leads to systematic changes in follicular gene expression.

The LH surge initiates the luteinization of preovulatory follicles and causes hormonal and structural changes that ultimately lead to ovulation and the formation of corpora lutea. The objective of the study was to examine gene expression in ovarian follicles (n = 11) collected from pigs (Sus scrofa domestica) approaching estrus (estrogenic preovulatory follicle; n = 6 follicles from two sows) and in ovarian follicles collected from pigs on the second day of estrus (preovulatory follicles that were luteinized but had not ovulated; n = 5 follicles from two sows). The follicular status within each follicle was confirmed by follicular fluid analyses of estradiol and progesterone ratios.

Large-scale generation and analysis of expressed sequence tags from porcine ovary.

One method to identify the factors that control ovarian function is to characterize the genes that are expressed in ovary. In the present study, cDNA libraries from fetal, neonatal, and prepubertal porcine ovaries, pubertal ovaries on different days of the estrous cycle (Days 0 [follicle], 5, and 12 [follicle and corpus luteum]), and follicles isolated from weaned sows (diameter, 2, 4, 6, and 8 mm) were constructed and sequenced. A total of 22 176 cDNAs were sequenced, of which 15 613 were of sufficient quality for clustering.