Summary: Recent advances in synthetic embryology have opened new avenues for understanding the complex events controlling mammalian peri-implantation development.Here, we show that mouse embryonic stem cells (ESCs) solely exposed to chemical inhibition of SUMOylation generate embryo-like structures comprising anterior neural and trunk-associated regions.HypoSUMOylation-instructed ESCs give rise to spheroids Hair Mask that self-organize into gastrulating structures containing cell types spatially and functionally related to embryonic and extraembryonic compartments.Alternatively, spheroids cultured in a droplet microfluidic device form elongated structures that undergo axial organization reminiscent of natural embryo morphogenesis.Single-cell transcriptomics reveals various cellular lineages, including properly positioned anterior neuronal cell types and paraxial mesoderm segmented into somite-like structures.
Transient SUMOylation suppression gradually increases DNA methylation genome wide and repressive mark deposition at Nanog.Interestingly, cell-to-cell variations in SUMOylation levels occur during early embryogenesis.Our approach provides a Condensate Pump proof of principle for potentially powerful strategies to explore early embryogenesis by targeting chromatin roadblocks of cell fate change.