Omics Views of Mechanisms for Cell Fate Determination in Early Mammalian Development

Abstract

During mammalian preimplantation development, a totipotent zygote undergoes several cell cleavages and two rounds of cell fate determination, ultimately forming a mature blastocyst. Along with compaction, the establishment of apicobasal cell polarity breaks the symmetry of an embryo and guides subsequent cell fate choice. Although the lineage segregation of the inner cell mass (ICM) and trophectoderm (TE) is the first symbol of cell differentiation, several molecules have been shown to bias the early cell fate through their inter-cellular variations at much earlier stages, including the 2- and 4-cell stages. The underlying mechanisms of early cell fate determination have long been an important research topic. In this review, we summarize the molecular events that occur during early embryogenesis, as well as the current understanding of their regulatory roles in cell fate decisions. Moreover, as powerful tools for early embryogenesis research, single-cell omics techniques have been applied to both mouse and human preimplantation embryos and have contributed to the discovery of cell fate regulators. Here, we summarize their applications in the research of preimplantation embryos, and provide new insights and perspectives on cell fate regulation.

Nuclear Distribution of the Chromatin-Remodeling Protein ATRX in Mouse Early Embryos during Normal Development and Developmental Arrest In Vitro

“…The unpolarized inner cells express the factors of pluripotency, generating ICM cells in the blastocyst [46]. Already at the morula stage and possibly even earlier, core transcription factors associated with pluripotency-such as SOX2, OCT4, and NANOG-are activated in the ICM, while a homeobox/ParaHox transcription factor CDX2, which also plays a significant role in development, is activated in TE cells [47].…”