Bioscientifica Proceedings

Abstract unavailableKeywords: inhibin; oestradiol; cow; pig; FSH© 1991 Journals of Reproduction & Fertility Ltd...

Summary. As previously described for the establishment of stable, pluripotent cell lines from pig blastocysts, an analogous cell line was isolated from a sheep blastocyst. There are common features in the morphologies and growth characteristics of the pig and sheep cells in culture; in particular, pig and sheep cells display large nuclei and relatively sparse cytoplasm, as is observed in mouse embryonic stem cells. Furthermore, the morphology of the sheep cell...

The corpus luteum is a transient gland, which is only functional for 17–18 days in the cyclic cow or for up to 200 days in the pregnant cow. Regression of the corpus luteum is essential for normal cyclicity as it allows the development of a new ovulatory follicle, whereas prevention of luteolysis is necessary for the maintenance of pregnancy. Evidence acquired over the past three decades indicated that PGF2α is the luteolytic hormone in ruminants. Neverthe...

The enhanced early embryonic survival in Chinese Meishan compared with Large- White gilts may be due, in part, to differences in ovarian and endocrine function, particularly during the periovulatory period. The overall patterns of oestradiol, LH and FSH secretion were not different between Meishan and Large-White hybrid controls during this period, although circulating inhibin concentrations were higher in Meishan gilts. Thus, there appeared to be a decreased sensitivity ...

There are many potential applications of transgenic methodologies for developing new and improved strains of livestock. One practical application of transgenic technology in pig production is to improve milk production or composition. The first week after parturition is the period of greatest loss for pig producers, with highest morbidity and mortality attributed to malnutrition and scours. Despite the benefits to be gained by improving lactation performance, little prog...

Embryogenesis is a complex process that is controlled at various levels. As new discoveries are made about molecular mechanisms that control development in other species, it is apparent that these same mechanisms regulate pig embryogenesis as well. Methylation of DNA and modification of histones regulate transcription, and mechanisms such as ubiquitinization, autophagy and microRNAs regulate development post-transcriptionally. Each of these systems of regulation is highl...

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

© 2013 Context Products Ltd...

Abstract unavailable© 2013 Context Products Ltd...

The autocrine and paracrine role of the insulin-like growth factors (IGFs) and epiderrnal growth factor (EGF)-related peptides in pig ovary are reviewed. For convenience, each of these regulatory systems is divided into several interactive components: regulated expression of the growth factors, growth factor reception at the cell surface and intracellular action of the growth factors. In addition, the concept of regulated bioavailability and targeting of growth factors in...