Compartmentalization and synergy of osteoblasts drive bone formation in the regenerating fin

This study investigated the cell composition and lineage relationships of FACS (fluorescence activated cell sorting)-enriched epidermal, bone forming (osteoblast) and (non-osteoblast) blastemal fin regenerate cells by single cell (sc) RNA sequencing. The repetitive cell harvesting in four-week intervals revealed a constant gene regulation over four successive regeneration rounds in the early outgrowth stage. In addition, the sc RNA dataset uncovered a potential lineage relationship between distal blastema cells and osteoblasts during fin regeneration. These findings, together with the identification of novel fin regenerate markers, advance our understanding of complex tissue regeneration in zebrafish. Overall design: To study potentially underrepresented cell populations during zebrafish fin regeneration, we harvested single cells and FACS-enriched for siam+, shha+, osterix+, RUNX2+ cells via respective mCherry and GFP reporter fluorophores. We performed gene expression analysis using data obtained from RNA seq of enriched cells from 4 successive regeneration stages at 3 dpa.