LIF signaling pathway regulates the heterogeneous Sox2 transcriptional dynamics in mESCs

The LIF signaling pathway is crucial for maintaining self-renewal and pluripotency in mESCs through regulation of factors like Sox2, yet its direct impact on Sox2 transcriptional dynamics remains elusive. Using PP7/PCP-mediated live imaging, we analyzed the transcriptional dynamics of Sox2 under LIF pathway perturbation at single-cell resolution. Removing LIF ligand or adding JAK inhibitor reduced the number of Sox2-active cells, while remaining Sox2-active cells exhibited decreased mRNA production. This reduction is characterized by smaller and less frequent transcriptional bursts, resulting in shorter active duration. Notably, LIF pathway perturbation decreased the number of pluripotent cells, with pluripotent marker-expressing cells showing higher Sox2 expression, suggesting a strong correlation between Sox2 levels and pluripotency maintenance. Additionally, Sox2 expression demonstrated transcriptional inheritance across cell cycles, with Sox2-active mother cells more likely to reactivate Sox2 post-mitosis – a memory mechanism maintained even during LIF pathway perturbation. Our findings reveal quantitative aspects of Sox2 regulation in pluripotency maintenance.