Searchable, peer-reviewed, open-access proceedings from bioscience and biomedical conferences

bp0001redr12 | (1) | REDR1980

Gonadotrophic control of follicular development and function during the oestrous cycle of the ewe

Baird DT , McNeilly AS

Summary. In the adult non pregnant ewe the secretion of FSH is sufficient to ensure a continuous growth and development of antral follicles to 3–5 mm size at all times. Further development and increased secretion of oestradiol through the final 72 h to ovulation depends on adequate stimulation by LH. During anoestrus and the luteal phase of the cycle LH pulses occur too infrequently to stimulate sufficient oestradiol to evoke an LH surge. Moreover, during...

bp0002rdr10 | Inhibin | REDR1990

Inhibin and oestradiol in the control of FSH secretion in the sheep

Baird DT , Campbell BK , Mann GE , McNeilly AS

Summary. In the sheep both FSH and LH are necessary for development of large antral follicles. The secretion of FSH is controlled by the negative feedback effect of two ovarian hormones, oestradiol and inhibin, acting at the level of the anterior pituitary. Both are derived from the granulosa cells of large antral follicles which are present in sheep ovaries throughout the oestrous cycle. FSH stimulates growth and mitosis and so the fully differentiated granul...

bp0002rdr14 | Regulation of Folliculogenesis | REDR1990

Gonadotrophic control of follicle growth in the ewe

McNeilly AS , Picton HM , Campbell BK , Baird DT

Summary. Preovulatory follicle growth in the ewe is dependent on FSH although no precise relationship appears to exist between plasma concentrations of FSH and the number of preovulatory follicles which develop or ovulation rate. This may be related to a hitherto unrecognized influence of pulsatile LH on the growth of large follicles. Preovulatory follicle growth is dependent on the presence of basal amounts of LH, but pulsatile LH, while being essential to su...

bp0005rdr27 | Genes Controlling Reproductive Performance | REDR2002

Bone morphogenetic proteins and folliculogenesis: lessons from the Booroola mutation

Souza CJH , Campbell BK , McNeilly AS , Baird DT

The Booroola phenotype is associated with a point mutation in the kinase domain of the bone morphogenetic protein receptor 1B (BMPR1B), and is characterized by 'precocious' differentiation of ovarian follicles, leading to the production of large numbers of ovulatory follicles that are smaller in diameter than wild-type follicles. These smaller follicles attain differentiation markers, such as expression of mRNA for P450aromatase and inhibin-ßA subunit, granulosa c...

bp0005rdr32 | Ruminant Models for Human Clinical Medicine | REDR2002

Domestic ruminants as models for the elucidation of the mechanisms controlling ovarian follicle development in humans

Campbell BK , Souza C , Gong J , Webb R , Kendall N , Marsters P , Robinson G , Mitchell A , Telfer EE , Baird DT

It is necessary to understand the basic physiology underlying the complex process of folliculogenesis to address common causes of infertility and to devise innovative strategies to increase the efficiency of assisted reproduction technologies. Availability of suitable ovarian tissue is a major constraint to research in this area in humans, and monovulatory domestic ruminants represent a physiologically relevant model to elucidate basic mechanisms before more focused clinical i...