TY - JOUR T1 - Embryonic signals perpetuate polar-like trophoblast stem cells and pattern the blastocyst axis JF - bioRxiv DO - 10.1101/510362 SP - 510362 AU - Javier Frias-Aldeguer AU - Maarten Kip AU - Judith ViviƩ AU - Linfeng Li AU - Anna Alemany AU - Jeroen Korving AU - Frank Darmis AU - Alexander van Oudenaarden AU - Clemens A. Van Blitterswijk AU - Niels Geijsen AU - Nicolas C. Rivron Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/03/06/510362.abstract N2 - The early mammalian conceptus (blastocyst) comprises an outer trophoblast globe that forms an axis originating from the inner embryonic cells. From the mouse conceptus, Trophoblast stem cells (TSCs) are derived, which are in vitro analogues of early trophoblasts. Here, we show that TSCs contain plastic subpopulations reflecting developmental states ranging from pre-to post-implantation trophoblasts. However, upon exposure to a specific combination of embryonic inductive signals, TSCs globally acquire properties of pre-implantation polar trophoblasts (gene expression, self-renewal) juxtaposing the inner embryonic cells, and an enhanced, homogeneous epithelial phenotype. These lines of polar-like TSCs (pTSCs) represent a transcriptionally earlier state that more efficiently forms blastoids, whose inner embryonic cells then induce the patterning of gene expression along the embryonic-abembryonic axis. Altogether, delineating the requirements and properties of polar trophoblasts and blastocyst axis formation in vitro provides a foundation for the precise description and dissection of early development. ER -