Abstract
Friend, Rauscher, and polycythemic viruses produce a marked erythrocytopoiesis in the spleens of infected mice. The erythrocytopoiesis induced by the Friend and Rauscher viruses can be inhibited in a hypertransfused polycythemic state. Like erythropoietin, the polycythemic virus can initiate erythropoiesis in this state. However, the mechanism by which the polycythemic virus initiates erythropoiesis in this state is not understood. These studies also show similarity of the Friend and Rauscher viruses in their erythropoietic response.