Comprehensive lineage tracing maps the landscape of cell fate decisions in mouse embryogenesis.

Lineage trees reconstructed with PEtracer reveal approximately 75% of cell divisions in mouse embryogenesis across over 1.4 million cells from 16 embryos.

• Why it matters: Understanding the cellular diversity and non-deterministic development in utero has been limited by the lack of comprehensive lineage maps, hindering insights into mammalian embryogenesis.
• What they did: The study used PEtracer to install heritable genetic marks during development, paired with transcriptional profiling to analyze lineage relationships, fate biases, and progenitor pools in multiple embryos.
• The result: Findings show highly reproducible lineage architecture and elucidate key developmental processes such as neural crest fate restriction, mesodermal contributions to endothelium, and axial elongation dynamics, advancing a predictive framework for mammalian development.