Erk activity at naïve:prime transition biases lineage specification during gastrulation [scRNA-seq]

FGF signaling is thought to be important for linegae specification during mouse develoipment. However, we have recently observed that FGF4 and FGF2 have opposing effects on Erk activity and ultimately on cell fate in both mouse embryonic stem cells and embryos. The aim of this study was to understand, at a single cell level, the impact in lineage specification of early exposure to FGF2 or FGF4 in gastruloid formation, a new 3D in vitro model of mouse gastrulation. Overall design: scRNA-Seq was performed on gastruloids primed with FGF2 or FGF4 for the first 48h (during naive to prime transition)