RESUMEN
How hematopoietic stem cells (HSCs) maintain the balance of self-renewal and differentiation could be partially ascribed to asymmetric and symmetric division patterns. However, a simple and effective method to detect stem cell division patterns is lacking. In this study, we introduce a strategy to describe stem cells division patterns with high spatial resolution at the single-cell level. We show that the fate determinant, Numb, exhibits low expression levels in HSCs that increase upon the initiation of differentiation. Using this single-cell immunofluorescence technique, we found that HSCs mainly undergo symmetric self-renewal in the presence of only stem cell factor, but with the addition of trombopoietin this division pattern is transformed into a symmetric commitment dominant mode in vitro. In addition, our study indicated that the division pattern cannot be defined by cell size or the nuclear/cytoplasm ratio. These findings collectively demonstrate that this single-cell immunofluorescence technique provides a new biological strategy in stem cell division research, and can be more widely applied given its flexibility, easy operability, and inexpensiveness.