Comparative transcriptomic analysis of in vivo and in vitro produced bovine 4-cell stage and 8-cell stage embryos

Pre-implantation embryos derived by in vitro fertilization differ in their developmental potential from embryos obtained in vivo. In order to characterize changes in gene expression profiles caused by in vitro culture environment, we employed microarray constructed from bovine embryo-specific cDNAs (BlueChip v., Université Laval, Québec) to compare in vitro cultured and in vivo derived bovine embryos at 4-cell and 8-cell stage. Analysis directly compared RNA samples from pool of 20 in vivo derived 4-cell stage embryos to RNA samples from pool of 20 in vitro cultured 4-cell stage embryos and RNA samples from pool of 20 in vivo derived 8-cell stage embryos to RNA samples from pool of 20 in vitro cultured 8-cell stage embryos. Three technical replicates, including one dye-swap array were prepared for each developmental stage (4-cell stage, 8-cell stage, respectively) .