XEN state reprogramming into self-organizing trophectoderm-like cells enables the assembly of synthetic embryoids

We established culture conditions that enable the two fates of blastocysts' extraembryonic lineages -- the primitive endoderm and the trophectoderm -- to co-exist in a shared XTE state. The XTE cells exhibit robust self-organization capacity and in combination with ES cells enable the assembly of blastocyst-like embryoids. We use single cell RNA-sequencing to characterise the three lineages (epiblast, primitive endoderm and trophectoderm) of the E4.5 blastocyst and compare transcriptionally these cells with the XTE/ES cells embryoids.