Navarro M. et al.
Embryonic stem cells (ESC) indefinitely maintain the pluripotent state of the blastocyst epiblast. Stem cells are invaluable for studying development and lineage commitment, and in livestock they constitute a useful tool for genomic improvement and in vitro breeding programs. Although these cells have been recently derived from bovine blastocysts, a detailed characterization of their molecular state is still lacking. Here, we apply cutting-edge technologies to analyze the transcriptomic and epigenomic landscape of bovine ESC (bESC) obtained from in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos. Bovine ESC were efficiently derived from SCNT and IVF embryos and expressed pluripotency markers while retaining genome stability. Transcriptome analysis revealed that only 46 genes were differentially expressed between IVF- and SCNT-derived bESC, which did not reflect significant deviation in cellular function. Interrogating the histone marks H3K4me3, H3K9me3 and H3K27me3 with CUT\&Tag, we found that the epigenomes of both bESC groups were virtually indistinguishable. Minor epigenetic differences were randomly distributed throughout the genome and were not associated with differentially expressed or developmentally important genes. Finally, categorization of genomic regions according to their combined histone mark signal demonstrated that all bESC shared the same epigenomic signatures, especially at promoters. Overall, we conclude that bESC derived from SCNT and IVF are transcriptomically and epigenetically analogous, allowing for the production of an unlimited source of pluripotent cells from high genetic merit organisms without resorting to genome editing techniques.
