Gene

Induced pluripotent stem cell

Gastrulation

Wnt signaling pathway

Embryonic stem cell

Germ layer

Embryo

Blastocyst

Genetics

Signal transduction

Epiblast

NODAL

Biology

Embryogenesis

Cell biology

Nature Communications

Following implantation, the human embryo undergoes major morphogenetic transformations that establish the future body plan. While the molecular events underpinning this process are established in mice, they remain unknown in humans. Here we characterise key events of human embryo morphogenesis, in the period between implantation and gastrulation, using single-cell analyses and functional studies. First, the embryonic epiblast cells transition through different pluripotent states and act as a source of FGF signals that ensure proliferation of both embryonic and extra-embryonic tissues. In a subset of embryos, we identify a group of asymmetrically positioned extra-embryonic hypoblast cells expressing inhibitors of BMP, NODAL and WNT signalling pathways. We suggest that this group of cells can act as the anterior singalling centre to pattern the epiblast. These results provide insights into pluripotency state transitions, the role of FGF signalling and the specification of anterior-posterior axis during human embryo development.

A single cell characterisation of human embryogenesis identifies pluripotency transitions and putative anterior hypoblast centre