Erythropoiesis in the Rat: Differential Rates of DNA Synthesis and Cell Proliferation

Abstract
Direct in vivo estimates of DNA synthesis time in early and late erythroblasts were obtained by using the H3- and C14-thymidine double-la-beling technique. A double-emulsion autoradiographic procedure was used to resolve the two isotopes. Early erythroblasts were found to proliferate at a rate about five times that of late cells. This results primarily from a shorter mean DNA synthesis time in early cells (2.5 hours) than in late cells (6.5 hours).