Effects of in vitro culture and of nutrition on epigenetic reprogramming in bovine oocytes and embryos

Abstract

Biotechnology of reproduction have contributed greatly to animal breeding programs and conservation of naturalized breeds in danger of extinction. According to the Annual Report of the IETS "International Embryo Transfer Society" in 2008, Brazil has the largest production of bovine embryos produced in vivo and in vitro in South America despite the large increase achieved with these technologies, their efficiency is still low. In vitro production of embryos, the quality of nutrition and body condition of donor oocytes, manipulation of oocytes and embryos and the environmental conditions in vitro, may affect the efficiency of the technique. A genetic event / physiological vital and specific gamete is an extensive epigenetic reprogramming is why these cells are suitable for fertilization and the formation of a viable embryo. The objective of this project is to test the effect of specific diets on epigenetic pattern in oocytes and embryos. Will be used oocytes and embryos produced in Nellore heifers exposed to different diets. Samples of DNA and RNA will be extracted for assessment of global methylation pattern of DNA methylation pattern in specific genes, quantification of the expression of genes involved in DNA methylation and characterization of the pattern of X chromosome inactivation in vivo under different diets. It is hoped that with better understanding the pattern of epigenetic reprogramming which is an important physiological event that should happen in gametogenesis, and mainly determine the effect of nutrition on these events in cattle. (AU)