Low expression of stem cell antigen-1 on mouse haematopoietic precursors is associated with erythroid differentiation

► Increased Sca1 expression on myeloid precursors inhibits erythroid differentiation. ► FDCP PU.1 (Sca1high) does not give rise red cells; FDCP SCL (Sca1low) does it. ► Increased Sca1 in myeloid precursors is related to the degree of cell quiescence. ► Preserving signals by Sca1 are crucial in the differentiation into erythrocytes.