Paracrine cell signaling is believed to be important for ovarian follicle development, and a role for some members of the fibroblast growth factor (FGF) family has been suggested. In the present study, we tested the hypothesis that FGF-8 and its cognate receptors (FGFR3c and FGFR4) are expressed in bovine antral follicles. RT-PCR was used to analyze bovine Fgf8, Fgfr3c and Fgfr4 mRNA levels in ...

The specification of polar, main-body and stalk follicle cells in the germarium of the Drosophila ovary plays a key role in the formation of the egg chamber and polarisation of its anterior-posterior axis. High levels of Notch pathway activation, resulting from a germline Delta ligand signal, induce polar cells. Here we show that low Notch activation levels, originating from Delta expressed in ...

The vitellogenin/very low density lipoprotein receptor (VTG/VLDL-R), a 95 kDa protein that belongs to the low density lipoprotein receptor gene family, mediates the uptake of yolk precursors by developing follicles during oocyte growth. However, the extent to which variation in VTG/VLDL-R expression plays a role in determining inter-individual variation in reproductive phenotype (e.g. follicle ...

To investigate the effect of thyroid hormone on the proliferative activity and apoptosis of granulosa cells at the varying stages of follicular growth, porcine granulosa cells obtained from small (1-2 mm), medium (3-5 mm) and large (6-11 mm) follicles were cultured under a serum-free condition in the presence or absence of follicle stimulating hormone (FSH; 20 ng/ml), with or without triiodothy...

There is large variation in dominant follicle diameter at the time of GnRH-induced ovulation in the CO-Synch protocol [a first GnRH injection on d -9 (GnRH1), followed by PGF(2alpha) on d -2, and a second GnRH injection (GnRH2) with timed AI on d 0], and the reason for the presence of small dominant follicles at GnRH2 is not known. Our hypothesis was that ovulatory response to GnRH1 and progest...

Bovine preantral follicles (40-100 microm diameter at collection) were collected from ovaries of slaughtered cows and cultured in vitro with one of the four treatments: follicle stimulating hormone (FSH; 100 ng/ml) alone; FSH plus epidermal growth factor (EGF; 100 ng/ml); FSH plus insulin-transferrin-selenium (ITS; +1%) or FSH plus hypoxanthine (4 mM) in tissue culture medium (TCM 199) suppleme...

BACKGROUND We have previously shown that suspension culture prevents follicle flattening and maintains three-dimensional follicle architecture better than culture on flat plates. However, many of the follicles cultured in suspension do eventually rupture, as basement membrane integrity is lost and the three-dimensional structure of the follicle is altered. Therefore, the objective of this study...

To clarify the morphological characteristics of the cynomolgus monkey immune system, we analyzed quantitative data on their lymphoid organs. Spleens, major lymph nodes and Peyer's patches were sampled from cynomolgus monkeys, and the lymphoid follicle and germinal center areas and percentages of CD3- and CD20-positive areas were calculated. All the organs analyzed showed large interindividual v...

Most estrous cycles in cows consist of 2 or 3 waves of follicular activity. Waves of ovarian follicular development comprise the growth of dominant follicles some of which become ovulatory and the others are anovulatory. Ovarian follicular activity in cows during estrous cycle was studied with a special reference to follicular waves and the circulating concentrations of estradiol and progestero...

The ovary receives a finite pool of follicles during fetal life. Atresia remains the major form of follicular expenditure at all stages since development of ovary. The follicular reserve, however, declines at an exponential rate leading to accelerated rate of decay during the years preceding menopause. We examined if diminished follicle reserve that characterizes ovarian aging impacts the attri...