Pluripotency and X chromosome dynamics revealed in pig pre-gastrulating embryos by single cell analysis

Abstract

High-resolution molecular programmes delineating the cellular foundations of mammalian embryogenesis have emerged recently. Similar analysis of human embryos is limited to pre-implantation stages, since early post-implantation embryos are largely inaccessible. Notwithstanding, we previously suggested conserved principles of pig and human early development. For further insight on pluripotent states and lineage delineation, we analysed pig embryos at single cell resolution. Here we show progressive segregation of inner cell mass and trophectoderm in early blastocysts, and of epiblast and hypoblast in late blastocysts. We show that following an emergent short naive pluripotent signature in early embryos, there is a protracted appearance of a primed signature in advanced embryonic stages. Dosage compensation with respect to the X-chromosome in females is attained via X-inactivation in late epiblasts. Detailed human-pig comparison is a basis towards comprehending early human development and a foundation for further studies of human pluripotent stem cell differentiation in pig interspecies chimeras.

Lineage specification and pluripotency revealed by transcriptome analysis from oocyte to blastocyst in pig

“…Then, we identified differentially expressed genes (DGEs) between ICM and TE, and a total of 2080 DGEs were found ( Figure 3C; Table S4). 17 Consistent with a recent report, 15,23 increased expression of GATA3 and GATA2 was observed in TE. 17 Consistent with a recent report, 15,23 increased expression of GATA3 and GATA2 was observed in TE.…”

“…15 In the study, we found that the overall expression trend of core and naïve pluripotent markers reported in mice and humans was high in the cells ( Figure 4A), confirming the signature of naïve pluripotency in porcine morula and ICM of EB. 15 In the study, we found that the overall expression trend of core and naïve pluripotent markers reported in mice and humans was high in the cells ( Figure 4A), confirming the signature of naïve pluripotency in porcine morula and ICM of EB.…”

“…Unsupervised hierarchical clustering (UHC; 19 813 genes) grouped the cells according to their developmental stage ( Figure 1B; Table S1), and we found that the MII oocyte, 1-cell and 2-cell embryo were separated from the embryos at the later stages from the 4-cell embryo to the EB. 15,20 More careful analysis showed that the cells from the morula were divided into two groups. 15,20 More careful analysis showed that the cells from the morula were divided into two groups.…”

“…15,17 In this study, we revealed that JAK-STAT, MAPKand PI3K-AKT signaling pathways were enriched in ICM, so we drew the expression profiles of the signaling pathways during oocyte to EB. 15,17 In this study, we revealed that JAK-STAT, MAPKand PI3K-AKT signaling pathways were enriched in ICM, so we drew the expression profiles of the signaling pathways during oocyte to EB.…”

“…15 The study provides a method to capture naïve ESCs from porcine embryo. Recent study has revealed the existence of naïve pluripotency signature in morula (E4-5) and ICM of early blastocyst (EB) (E5-6) in pig.…”