Fig. 1

Lentiviral CRISPR-guide RNA library infection. a FACS analysis gating strategies. b FACS analysis of Procr expression in CommaDβ cells. Out of total CommaDβ cells, 0.15% of cells have endogenous Procr expression (Procr⁺). c Procr⁻ or Procr⁺ CommaDβ cells were isolated and separately cultured for 10 days. FACS analysis of cultured cells showed similar Procr⁺ cell fractions regardless of their culture origin. d CommaDβ cells with stable Cas9 expression were infected with lentiviral CRISPR-guide RNA library. After 2 days, cells were treated with puromycin for 48 h for positive selection. After puromycin selection, cells were further cultured for 2–3 days in fresh medium before FACS analysis for Procr expression