Bioscientifica Proceedings

Summary. Maternal recognition of pregnancy in sheep, cattle and goats involves physiological mechanisms that result in protection of corpora lutea from luteolysis by modification or inhibition of uterine production of luteolytic pulses of prostaglandin (PG) F-2α. Ovine, bovine and caprine luteal cells release oxytocin in a pulsatile manner during late dioestrus. Oxytocin then binds to its endometrial receptors and initiates luteolytic pulses of PGF-2&#945...

Annual variations in the secretion of LH are responsible for seasonal changes in ovulatory activity in ewes. This hormonal pattern reflects an increase in the intensity of the negative feedback exerted by oestradiol under long days. Neuro-pharmacological studies have shown that this inhibition of LH secretion involves activation of catecholaminergic systems from preoptic and mediobasal hypothalamus (MBH) by oestradiol during anoestrus, and that 5-hydroxytryptamine inputs may a...

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...

Summary. Microbes commonly infect the female genital tract of cattle, causing uterine disease, abortion, and infertility. In particular, postpartum uterine disease develops in about 40% of dairy cows following infections with Gram-negative Escherichia coli and Gram-positive bacteria, such as Trueperella pyogenes. These infections damage tissues and cause inflammation in the endometrium, and perturb follicle growth and function in the ovar...

The development of new technologies that would increase the efficiency for generation of transgenic livestock and would overcome some of the problems associated with random insertion of the transgene will greatly benefit animal agriculture. A potential alternative technology to pronuclear injection for the generation of transgenic pigs involves the isolation, culture and genetic manipulation of cell lines that can be reintroduced into the embryo for participation in the f...

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 ...

Functional genomics is an experimental approach that incorporates genomewide or system-wide experimentation, expanding the scope of biological investigation from studying single genes to studying potentially all genes at once in a systematic manner. This technology is highly appealing because of its high throughput and relatively low cost. Furthermore, analysis of gene expression using microarrays is likely to be more biologically relevant than the conventional paradigm ...

Commercial, North American pork breeds (Sus sada) experience significant loss of genetically-normal conceptuses during the peri-implantation (attachment) period and at mid-gestation (day 50 to 90 of the 114 day porcine gestation interval). Although exact causes for these losses are not defined, asynchronous in-utero development and deficits in vascularization of the endometrium and placenta appear to be involved. Understanding of normal maternal-fetal dialogue is critica...

Abstract unavailable© 2009 Society for Reproduction and Fertility...

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...