Project description:In mammalian preimplantation development, pluripotent cells are set aside from cells that contribute to extra-embryonic tissues. Although the pluripotent cell population of mouse and human embryos can be cultured as embryonic stem cells, little is known about the pathways involved in formation of a bovine pluripotent cell population, nor how to maintain these cells in vitro. The objective of this study was to determine the transcriptomic profile related to bovine pluripotency. Therefore, in vitro derived embryos were cultured in various culture media that recently have been reported capable of maintaining the naïve pluripotent state of human embryonic cells. Gene expression profiles of embryos cultured in these media were compared using microarray analysis and quantitative RT-PCR. Compared to standard culture conditions, embryo culture in 'naïve' media reduced mRNA expression levels of the key pluripotency markers NANOG and POU5F1. A relatively high percentage of genes with differential expression levels were located on the X-chromosome. In addition, reduced XIST expression was detected in embryos cultured in naïve media and female embryos contained fewer cells with H3K27me3 foci, indicating a delay in X-chromosome inactivation. Whole embryos cultured in one of the media, 5iLA, could be maintained until 23 days post fertilization. Together these data indicate that 'naïve' conditions do not lead to altered expression of known genes involved in pluripotency. Interestingly, X-chromosome inactivation and development of bovine embryos were dependent on the culture conditions.
Project description:Affymetrix Human GeneChips are used to profile gene expression of bovine tissues and embryos to identify uniquely expressed genes in bovine in-vitro fertilized embryos by comparing with seven bovine adult tissues through gene clustering
Project description:The process of early development of mammals is subtly and accurately controlled by the regulation networks of embryo cells. Time course expression data measured at different stages during early embryo development process can give us valuable information by revealing the dynamic expression patterns of genes in genome wide scale. In this study, bovine embryo expression data were generated at oocyte, one cell stage, two cell stage, four cell stage, eight cell stage, sixteen cell stage, morula, and blastocyst; Human embryo expression data were generated at one cell stage, two cell stage, four cell stage, eight cell stage, morula, and blastocyst; Mouse embryo expression data were generated at one cell stage, two cell stage, four cell stage, eight cell stage, morula, and blastocyst. Experiment Overall Design: Bovine, Human, and Mouse embryos were harvested at successive stage from oocyte to blastocyste. Total RNAs were extracted, amplified and hybridized onto Affymetrix microarrays.