BACKGROUND Little is known about the factors that control the initiation of growth of primordial follicles. Primordial follicles in pieces of fetal bovine ovarian cortex spontaneously activate in vitro and develop to the primary stage, but few follicles develop further. For decades, embryologists have grafted tissue to the chorioallantoic membrane (CAM) of chick embryos to study the development...

introduction: the origin of neonatal oocyte development is unknown. however, estrogen plays an essential role during development of the female reproductive system. anastrozole is used as both ovulation stimulating and an anticancer drug. the aim of this study was to evaluate the impact of anastrozole on follicular development and differentiation in mice. materials and methods: in the present st...

background:   objective: the aim of this study was to evaluate the in vitro developmental competence of mouse vitrified pre-antral follicles in comparison to isolated pre-antral follicles derived from vitrified ovaries in the presence of alpha lipoic acid (ala).   materials and methods: pre-antral follicles derived from fresh, vitrified-warmed ovarian tissues and vitrified–warmed pre-antral fol...

background: one of the most major obstacles of ovarian tissue vitrification is suboptimal developmental competence of follicles. matrix metalloproteinases 2 (mmp-2) and 9 (mmp-9) and their tissue inhibitors timp-1 and timp-2 are involved in the remodeling of the extracellular matrix in the ovaries. objective: this study aimed to evaluate the expression of mmp-2, mmp-9, timp-1, and timp-2 genes ...

the aim of the present study was to investigate the effect of follicle stimulating hormone (fsh) on survival, activation and growth of ovine primordial follicles using histological studies. pieces of ovine ovarian cortex were obtained and cultured for 6 days in minimum essential medium supplemented with or without fsh (50 ng/ml). these fragments were then process to be used for histology compar...

Physiologically, the size of the primordial follicle pool determines the reproductive lifespan of female mammals, while its establishment largely depends on a process of germline cyst breakdown during the perinatal period. The mechanisms regulating this process are poorly understood. Here we demonstrate that c-Jun amino-terminal kinase (JNK) signaling is crucial for germline cyst breakdown and ...

Ovaries contain follicles at various stages of development, including primordial, primary, secondary, antral and Graafian follicles. Although the growth of these follicles is controlled to maintain regular ovulation, the mechanism through which this occurs remains unclear. In our study, we found that the growth rate of cultured secondary follicles separated from mice ovaries differed between fo...

We hypothesized that the ovulatory response of one ovary to FSH would be related positively to the size of the primordial and growing pools of follicles in the other ovary. Nonlactating cows (n = 26) were unilaterally ovariectomized and 2 days later were superovulated. The superovulatory response was classified as Low (< 5 corpora lutea [CL]), Medium (5-14 CL), or High (> 14 CL). Surface follic...

Ovarian follicles are a major site of oestrogen synthesis in sheep, but almost nothing is known about the relative contribution made by follicles of different sizes to the output of oestrogen at various stages of the reproductive cycle. To determine this, ovaries were dissected from sheep, all follicles over 2 mm in diameter were explanted separately as organ cultures and the daily production o...

Localization of androgen receptor (AR) was investigated in ovarian follicles developing and undergoing atresia during pregnancy in the pig. Immunohistochemical staining was conducted on ovarian antral follicles isolated on different days of gestation: 10, 18, 32, 50, 70, and 90. Paraffin sections were also subjected to in situ DNA labeling. TUNEL staining revealed the presence of positive folli...