Generation of erythroid cell cultures with restricted and extensive self-renewal from embryonic, fetal, and adult hematopoietic tissues derived from ICR mice. No restricted or extensively proliferating erythroid cultures could be established from E7.5 yolk sac (YS) cells. Cultures of erythroid cells with restricted self-renewal potential were generated from later YS, fetal liver (FL), spleen, and bone marrow (BM). The highest frequency of erythroid cultures exhibiting extensive self-renewal potential was derived from E8.5-E14.5 embryos, which is associated with the emergence of a transient wave of definitive erythroid potential in the yolk sac and its transition to the early fetal liver. Cultures derived from “stressed” BM and spleen from mice made anemic with phenylhydrazine were only capable of restricted self-renewal.