A genome-wide CRISPR-Cas9 knockout screen identifies essential and growth-restricting genes in human trophoblast stem cells

The recent derivation of bona fide human trophoblast stem cells (hTSCs) significantly improved our ability to study human placental biology and pathologies, but few studies have investigated the molecular regulators of hTSC identity. Therefore, we utilized a genome-wide CRISPR-Cas9 knockout screen to comprehensively define genes essential for or restricting the fitness of hTSCs. The resulting essential and growth-restricting genes include both well-established and potentially novel trophoblast regulators. We referenced our data to those of similar genetic screens performed in cancer cell lines and primed human pluripotent stem cells (hPSCs), as well as gene expression data of the early human embryos, to identify potential hTSC-specific and -enriched regulators. Among those are TEAD1, a gene previously reported to be dispensable for mouse placentation6. However, in the human trophoblast context, TEAD1 targets many hTSC regulators and plays a major role in its specification and maintenance. Overall, our study presents the first CRISPR/Cas9 knockout screen in a human extraembryonic lineage and provides a valuable resource for future trophoblast research. CRISPR screening in hTSCs TEAD1 CUT&Tag in hTSCs ATAC-seq in naïve hPSCs