
마우스 배아의 세포 극성화 시기가 비동기적이며, 이는 4세포기 이전부터 존재하는 세포 간 비대칭성과 관련이 있다. 조기 극성화 세포는 대칭적 세포 분열과 영양외배엽 세포 운명으로 편향된다.


coremsg

The first lineage allocation in mouse and human embryos separates the inner cell mass (ICM) from the outer trophectoderm (TE). This symmetry breaking event is executed through polarization of cells at the 8-cell stage and subsequent asymmetric divisions, generating polar (TE) and apolar (ICM) cells. Here, we show that embryo polarization is unexpectedly asynchronous. Cells polarizing at the early and late 8-cell stage have distinct molecular and morphological properties that direct their following lineage specification, with early polarizing cells being biased towards producing the TE lineage. More recent studies have also implicated heterogeneities between cells prior to the 8-cell stage in the first lineage allocation: cells exhibiting reduced methyltransferase CARM1 activity at the 4-cell stage are predisposed towards the TE fate. Here, we demonstrate that reduced CARM1 activity and upregulation of its substrate BAF155 promote early polarization and TE specification. These findings provide a link between asymmetries at the 4-cell stage and polarization at the 8-cell stage, mechanisms of the first lineage allocation that had been considered separate.

### Competing Interest Statement

The authors have declared no competing interest.

Asynchronous mouse embryo polarization leads to heterogeneity in cell fate specification

마우스-배아의-비동기적-극성화로-인한-세포-운명-결정의-이질성


마우스 배아의 비동기적 극성화로 인한 세포 운명 결정의 이질성
