Ovulation has long been recognized as one of the most dramatic reproductive processes. Decades of research on how the LH/FSH surge leads to ovulation have made it clear that the surge induces a very complex cascade of changes. Studies of genetically modified mice have pointed to progesterone (P4) and its receptor (PGR) and the prostaglandins (PGs) as critical components of the ovulatory cascade...

Polyadenylated RNA prepared from pituitary glands of normal and castrate rats was translated in membrane-free heterologous cell-free systems derived from wheat germ and rabbit reticulocytes. Sodium dodecyl sufate (SDS)-polyacrylamide gel electrophoresis and autoradiography demonstrated a major [35S]methionine-labeled translation product of castrate pituitary mRNA with apparent Mr = 14,000. This...

The purpose of this study was to evaluate the effectiveness cysteamine supplementation on maturation medium and/or in vitro fertilization with regards improving normal rate sheep oocytes, which are characterized by formation two pronuclei. Grade A and B oocytes were matured medium-199 0.3% bovine serum albumin (BSA), 10 IU/mL follicle stimulating hormone (FSH), human chorionic gonadotrophin (hC...

The objective of this study was to examine the influence of 17 beta-estradiol (E2) on distribution of LH and FSH isoforms during the follicular phase of the bovine estrous cycle prior to the preovulatory surges of LH and FSH. On Day 16 of the estrous cycle (Day 0 = estrus), intact controls (CONT; n = 4) were treated with prostaglandin F2 alpha (PGF2 alpha) to induce luteal regression and initia...

The main role of the ovarian granulosa cells is to nurse the oocyte and to produce estradiol and progesterone upon stimulation by gonadotropins. In fact, follicle-stimulating hormone (FSH) and luteinizing hormone control the expression of several genes during granulosa cell differentiation via cyclic AMP-dependent phosphorylations. Cyclic AMP stimulates transcription of genes that carry the cAM...

Sexually mature gilts (n = 20) were actively immunized against GnRH. Primary and booster immunizations of GnRH conjugated to bovine serum albumin induced production of antibodies in all gilts. Nineteen of the gilts became acyclic with suppressed concentrations of gonadotropins and estradiol. Intravenous challenges with 100 micrograms GnRH and 5 micrograms D-(Ala6, des-Gly-NH2(10)) ethylamide Gn...

The aim of this study was to determine the individual and combined effect of activin and follicle stimulating hormone (FSH) on somatic and germ cell development in cultured pre-antral follicles. Pre-antral bovine follicles (mean diameter 157 +/- 3, range 132-199 microm) were cultured for 8 days in serum-free medium in the presence of either 100 ng/ml of recombinant human activin A (rhAct A), 10...

This study assessed the participation of amphiregulin (AREG) and bone morphogenetic protein 15 (BMP15) during maturation of bovine cumulus-oocyte complexes (COCs) on cumulus cell function and their impact on subsequent embryo development. AREG treatment of COCs enhanced blastocyst formation and quality only when in the presence of BMP15. Expression of hyaluronan synthase 2 was enhanced by folli...

The a-subunit is common to the family of heterodimeric glycoprotein hormones FSH, LH, TSH and the placerual chorionic gonadotropin (CG). Clones coding for the pre a-subunit of the pituitary glycoprotein hormones were isolated from a lamb pituitary XgtlO cDNA library [1] using a synthetic oligonucleotide probe based on the published amino acid sequence of the ovine a-subunit [2] and nucleotide s...