Single-cell multiomics analysis reveals CTCF as a key regulator of lung morphogenesis and progenitor maintenance.

Lung development generates a complex tree-like architecture through proximal-distal patterning and branching morphogenesis. However, the gene regulatory programs governing embryonic lung development remain poorly understood. Here, we present a comprehensive single-cell multi-omics atlas of mouse embryonic lungs, integrating gene expression and chromatin accessibility profiles. Through systematic analysis, we identify 13 distinct cell types and map cis-regulatory elements, peak-to-gene linkages, and transcription factors underlying lung development. Leveraging this multi-modal dataset, we uncover lineage-determining transcription factors driving cell differentiation, including the Activated Protein-1 complex. We further delineate gene regulatory networks involving diverse transcription regulators, including CCCTC-binding factor (CTCF). Using the Ctcf conditional knockout mouse, coupled with histological and multi-omics analyses, we demonstrate that CTCF orchestrates lung progenitor maintenance and branching morphogenesis by modulating both gene expression and chromatin accessibility. Thus, our study provides a multi-omics resource and mechanistic insights for transcriptional regulation of lung morphogenesis.