Analogs of gonadoliberin (GnRH) are widely used in cattle to synchronize estrus and to induce ovulation, as well as for the treatment of ovarian cysts. The aim of this study was to compare the plasma profiles of LH and progesterone and the follicular dynamics in response to the administration of gonadorelin, lecirelin, or buserelin at the dose recommended to induce ovulation. In addition, the b...

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide originally purified from ovine hypothalamus for its potent activity to stimulate cAMP production. However, its presence and action have also been demonstrated in various peripheral tissues including the ovary. In the zebrafish, two forms of PACAP (PACAP(38)-1, adcyap1a; and PACAP(38)-2, adcyap1b) and three PACAP recept...

Oestrogens are pivotal in ovarian follicular growth, development and function, with fundamental roles in steroidogenesis, nurturing the oocyte and ovulation. Infections with bacteria such as Escherichia coli cause infertility in mammals at least in part by perturbing ovarian follicle function, characterised by suppression of oestradiol production. Ovarian follicle granulosa cells produce oestra...

The purpose of the studies reported in this thesis was to provide a better understanding of the effects of purified ovulation-inducing factor (OIF) from llama seminal plasma in reflex ovulators (lama glama) and spontaneous ovulators (Bos taurus). The objective of the first study was to determine if the dose of OIF of llama seminal plasma required to elicit ovulation is physiologically relevant,...

background: in patients with anovulatory infertility the first choice of treatment for ovulation induction is an antiestrogen, most commonly clomiphene citrate (cc). however, 20-25% of the women are resistant to cc and do not ovulate perhaps due to antiestrogenic mechanism of the cc action, which involves long-lasting estrogen receptor (er) depletion. objective: the objective of the study was t...

Maternal heat stress reduces oocyte competence for fertilization and post-fertilization development, but the mechanism is unknown. The present experiment investigated two potential mechanisms: (1) reduced oxygen delivery to the preovulatory follicle (due to increased thermoregulatory vascular perfusion of skin and respiratory tract); (2) reduced follicular steroid synthesis. These hypotheses we...

puckered (puc) encodes a VH1-like phosphatase that down-regulates Jun kinase (JNK) activity during dorsal closure of the Drosophila embryo. We report a role for puc in follicle cell morphogenesis during oogenesis. puc mRNA accumulates preferentially in the centripetally migrating follicle cells and cells of the elongating dorsal appendages. Proper levels of Puc activity in the follicle cells ar...