A novel inducible cell lineage tracing system for simultaneous fluorescence cell labeling and single-cell clonal reconstruction

In vivo clonal analysis utilizing recombinase-activated fluorescence cell labeling has become an essential method for visualizing stem cell activities and cell lineage formation. Recently, the simultaneous acquisition of cell lineage information and single-cell transcriptome data has further advanced our understanding of clonal cell evolution during development, tissue homeostasis, and disease progression. Here we present a novel inducible cell lineage tracing system, called TiTracer, which simultaneously activates fluorescence cell labeling and cellular barcode generation by transiently expressing template independent terminal transferase (TdT) and I-SceI homing endonuclease. We applied this system in HEK293T cells and primary mouse keratinocytes and performed single-cell RNA-seq for barcode recovery and clonal reconstruction. Overall design: single cell RNA-seq of mouse keratinocytes