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

bp0004rdr28 | Local Cellular and Tissue Communication | REDR1998

Growth factors and extracellular matrix proteins in interactions of cumulus–oocyte complex, spermatozoa and oviduct

Einspanier R , Gabler C , Bieser B , Einspanier A , Berisha B , Kosmann M , Wollenhaupt K , Schams D

The expression and localization of selected growth factor systems and extracellular matrix (ECM) components that may influence oocyte maturation and fertilization within the mammalian oviduct are reported. Fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) systems could be detected by use of RT–PCR, RNase protection assay (RPA) and immunohistochemistry in bovine follicles, bovine cumulus–oocyte complexes (COC) and bovine and marmoset oviduct...

bp0005rdr7 | Gamete-Somatic Cell Interactions | REDR2002

Mechanisms regulating follicular development and selection of the dominant follicle

Webb R , Nicholas B , Gong JG , Campbell BK , Gutierrez CG , Garverick HA , Armstrong DG

Reproductive function is an integrated process encompassing both extraovarian signals, such as gonadotrophins, and intrafollicular factors, such as locally produced growth factors. Initiation of primordial follicle growth and the early stages of folliculogenesis can occur without gonadotrophins. However, in vivo and in vitro studies indicate that FSH may stimulate the rate of preantral follicle growth and that it can take only 3 months for a primordial follic...

bp0006rdr2 | Male Reproduction | REDR2006

Seminal plasma effects on sperm handling and female fertility

Maxwell WMC , de#Graaf SP , Ghaoui R#El-Hajj , Evans G

The components of ruminant seminal plasma and their influence on the fertility of spermatozoa are reviewed. Seminal plasma can both inhibit and stimulate sperm function and fertility through the multifunctional actions of organic and inorganic components. These effects are now better understood because the composition of the seminal plasma, including its protein content and that of other structures, specifically membrane vesicles, has been clarified. Spermatozoa gain motility ...

bp0010ised9 | (1) | ISED2019

Lipid droplet utilization by the mouse embryo

Bisogno S , Arena R , Fic K , Gąsior Ł , Ptak GE

High numbers of lipid droplets (LDs) in mammalian eggs are stored and maintained throughout embryo development without marked signs of their utilization. It was previously demonstrated in large domestic mammals that removing lipids from the zygote does not influence post-implantation development in terms of the rate of delivered offspring. Previously studied pig and cow eggs contain considerable amounts of LDs, while mice have a very low level of ooplasmic lipids, which allows...

bp0010ised13 | (1) | ISED2019

Trophectoderm and embryoblast proliferate at slow pace in the course of embryonic diapause in the roe deer (Capreolus capreolus)

Rüegg AB , Bernal S , Moser FN , Rutzen I , Ulbrich SE

The European roe deer (Capreolus capreolus) was the first mammal in which embryonic diapause has been described. While diapause is characterized by a complete developmental arrest in some species, roe deer blastocysts show a very slow, yet continuous growth. To date, it is neither known whether this growth is accompanied by developmental progression nor whether it is uniform in both, the trophectoderm (TE) and the inner cell mass (ICM). We collected roe deer blastocysts during...

bp0013cpr10 | Ovarian Function | CPR1989

The synthesis and actions of steroids and prostaglandins during follicular maturation in the pig

Ainsworth L. , Tsangt B. K. , Downey B. R. , Marcus G. J.

Summary. Our understanding of the synthesis and production of follicular steroids and prostaglandins (PG) in the pig is based largely on in-vitro studies with granulosa and theca interna tissues obtained from Graafian follicles at various stages of maturation. As the follicle enlarges before the LH surge, granulosa cells exhibit a decrease in FSH receptors and are less responsive to FSH in terms of cAMP production. Concurrently, there is an increase in gr...

bp0014cpr7 | Ovarian and Uterine Function | CPR1993

Early uterine development in pigs

Bartol F. F. , Wiley A. A. , Spencer T. E. , Vallet J. L. , Christenson R. K.

The capacity of pig uterine tissues to recognize and respond to maternal and conceptus signals determines whether pregnancy can be established and defines the environment in which embryonic and fetal growth occur. Limits of uterine capacity may be defined genetically. However, the extent to which functional uterine capacity approaches genetic potential may be determined, in part, by the success of organizational events associated with growth, morphogenesis and cytodiffere...

bp0014cpr20 | Components of Prolificacy in Pigs | CPR1993

Uterine function in Meishan pigs

Christenson R. K. , Vallet J. L. , Leymaster K. A. , Young L. D.

The Meishan pig provides a biological model with the genetic capacity to express a high prolificacy. This prolificacy can be partially attributed to a higher ovulation rate and a higher rate of prenatal survival at a given ovulation rate throughout gestation than in European breeds. Both early embryonic survival (factors inherent to the ovum and uterus, which occur before day 25 of gestation) and uterine capacity (factors inherent to uterine limitation, which occur from 3...

bp0016cpr17 | Gestation and Parturition | CPR2001

Causes and conseq uences of fetal growth retardation in pigs

Ashworth C. J . , Finch A. M. , Page K. R. , Nwagwu M. O. , McArdle H. J.

In pigs, as in other species, fetal growth retardation is associated with reduced birth weight and increased risk of fetal and neonatal death. As there are few opportunities after birth to remedy the detrimental effects of low birth weight, it is important to understand both the intrinsic and extrinsic factors associated with inadequate fetal growth and to determine when growth retarded fetuses deviate from the growth trajectory of their normal sized littermates. Inadequately ...

bp0017cpr7 | (1) | CPR2005

The growth hormone/prolactin gene family in ruminant placentae

Raeside J. I. , Christie H. L. , Renaud R. L. , Sinclair P. A.

A review of the remarkable production of steroids by the testes of the boar is presented, with the principal aims of highlighting the achievements of the Leydig cells and, at the same time, pointing to the considerable deficiencies in our understanding of its biological relevance. The onset of gonadal steroidogenesis at an early stage of sex differentiation and the pattern of pre- and postnatal secretion of steroids are outlined. This is followed by a list of steroids id...