Erythroid cells analyzed in this study are all at similar stages of differentiation. (A) May-Grünwald Giemsa (MGG)–stained touch preparations from the spleens of phenylhydrazine-treated adult mice. Images were captured using a Nikon eclipse E600 microscope with a Nikon DXM1200C digital camera using NIS elements BR2.30 SP4 imaging software (all from Nikon UK). Original magnification 60×/1.40 NA oil objective (Nikon Japan) for all panels. (B) Flow cytometric analyses of mouse primary erythroblasts. Ter119⁺ erythroid cells were auto–magnetic-activated cell sorting–purified from the spleen of phenylhydrazine-treated adult mice and restained with anti-CD71 to show the equivalent maturation stages in all mice examined.