Bioscientifica Proceedings

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

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

This review highlights information on conceptus-uterus interactions in the pig with respect to uterine gene expression in response to estrogens and interferons (IF Ns) secreted from elongating conceptuses. Pig conceptuses release estrogens for pregnancy recognition, but also secrete IENs that do not appear to be antiluteolytic. Estrogens and IFNs induce expression of largely non-overlapping sets of genes, and evidence suggests that pig conceptuses orchestrate essential e...

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

During mammalian diapause, the embryo is arrested at the blastocyst stage. In diapausing carnivores and marsupials, growth arrest of the blastocyst is coincident with a quiescent corpus luteum (CL). In the roe deer, progesterone is produced throughout diapause and the blastocyst exhibits very slow growth. To date, early roe deer embryos of known age have not been described. Therefore, it is not known at which stage and at what pace the roe deer embryo enters diapause. To colle...

The phenomenon of embryonic diapause has been reported to possibly affect ovarian follicular development. The aim of the current study was to identify the impact of the embryonic diapause period on follicle number and oocyte quality in the European roe deer (Capreolus capreolus). In this species, the embryo undergoes five months of developmental delay. We have determined the antral follicle count (AFC), oocyte morphological quality, oocyte meiotic resumption capacity ...

Manipulation of the pig genome is currently restricted to the random insertion of new DNA using pronuclear microinjection. This method suffers from a number of inherent limitations, the majority of which result from the inability to control the site at which the transgene becomes integrated. These drawbacks, together with the need to be able to target existing genes, will result in the replacement of pronuclear injection by new methods that have the capability to direct i...

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...

Summary. Declining fertility and perturbations in reproductive development in a variety of species have been linked to exposure to endocrine disrupting chemicals (EDCs), which are ubiquitous in the environment. Ruminants are largely exposed to such chemicals in sewage sludge fertiliser widely used in animal production systems. This has been investigated experimentally through the deliberate exposure of pregnant ewes to sewage sludge fertilised pastures or cont...

Summary. Recent research clearly shows that fusion genes can be microinjected into a pronucleus of an ovum and integrate into the pig genome. Animals with such fusion genes are called ‘transgenic’. The percentage of injected ova that developed into transgenic pigs varied among experiments from 0.31% to 1.73%. The percentage of transgenic pigs that expressed the fusion gene ranged from 17% to 100%.Eleven different regulatory s...