Editors Assessment:
This is a Data Release paper describing a mouse embryoid body single-cell RNA-seq dataset generated to study how oxygen availability shapes early cell differentiation. Acosta-Iborra et al. differentiated R1 mouse embryonic stem cells into embryoid bodies for 8 or 10 days, exposing them to hypoxia or normoxia for the final 16 or 48 hours of differentiation, then profiled thousands of cells per condition using droplet-based scRNA-seq from 10X. This yielding eight raw/filtered HDF5 count matrices across the four conditions. This was validated with flow cytometry, immunofluorescence, and EdU assays, confirming that hypoxia increased endothelial marker expression and vascular network complexity while inducing cell cycle arrest. This pattern mirrored transcriptionally, with hypoxic samples showing markedly higher proportions of cells in G0/G1 phase and elevated hypoxia gene-signature scores. QC analysis (and peer review in GigaByte) confirmed high data quality across samples, and conservative low-resolution clustering revealed a largely homogeneous progenitor population with a smaller, more differentiated subset. While there are limitations (mature endothelial cells were too sparse to robustly test the original hypothesis) the authors present this as an open, well-validated resource for comparative studies of hypoxia responses, benchmarking single-cell computational tools, and investigating early lineage specification and oxygen signaling more broadly.
This evaluation refers to version 1 of the preprint