Regulation of Erythropoiesis in the Friend Leukemia Mouse

Friend leukemia infection in ddO mice produced a marked increase in the erythropoietic activity of the affected mice. By the fact that the increased erythropoietic activity was not suppressed by the transfusion polycythemia and that the plasma and spleen extract of the infected animal showed no erythropoietic activity, it is postulated that erythropoiesis in Friend leukemia is governed by mechanisms other than normal ones. The possible role of the virus in differentiating the stem cell into erythroblasts is discussed.