Transcriptional and epigenetic control of cell fate decisions in early embryos.

Ramiro Alberio

doi:10.1071/rd17403

Abstract

Mammalian embryo development is characterised by regulative mechanisms of lineage segregation and cell specification. A combination of carefully orchestrated gene expression networks, signalling pathways and epigenetic marks defines specific developmental stages that can now be resolved at the single-cell level. These new ways to depict developmental processes have the potential to provide answers to unresolved questions on how lineage allocation and cell fate decisions are made during embryogenesis. Over the past few years, a flurry of studies reporting detailed single-cell transcription profiles in early embryos has complemented observations acquired using live cell imaging following gene editing techniques to manipulate specific genes. The adoption of this newly available toolkit is reshaping how researchers are designing experiments and how they view animal development. This review presents an overview of the current knowledge on lineage segregation and cell specification in mammals, and discusses some of the outstanding questions that current technological advances can help scientists address, like never before.

Highlights

Mammalian embryo development follows a regulatory series of lineage segregation events that culminate with the specification of more than 200 different cell types that form the adult animal
The apical domain of blastomeres confers differential contractility, and cells with reduced contractility contribute to the inner cell mass (ICM), suggesting mechanical sensing is important during lineage segregation (Maıtre et al 2016)
The mammalian embryo is highly adaptable to the removal or addition of blastomeres, in mice epigenetic differences become apparent in blastomeres of 4-cell embryos, which influence how the pluripotency factors octamer-binding transcription factor 4 (Oct4) and SRY-box 2 (Sox2) contribute to the commitment of ICM cells during the first lineage segregation (Goolam et al 2016; White et al 2016)

Summary

Introduction

Mammalian embryo development follows a regulatory series of lineage segregation events that culminate with the specification of more than 200 different cell types that form the adult animal. Bovine and porcine embryos, GATA6 is expressed in cleavage stages and all cells of the blastocyst, it is not a suitable markers for PE segregation (Kimber et al 2008; Roode et al 2012; Cao et al 2014; Wei et al 2017).

Results

Conclusion