Morphologic appearance of erythroid cells in spleen after PHZ. (A-B,E-H) May-Grünwald-Giemsa stain. (C-D) Benzidine/hematoxylin stain. (A) Smears from control spleens at day 4 after PHZ treatment. Note the predominant presence of erythroid cells. Nonerythroid cells were 34% plus or minus 4%; n = 7. (B) In β₁^Δ/Δ spleens, proportionally fewer erythroid cells were present (from 20%–30%; nonerythroid cells were 78 ± 3%, n = 3) and of less mature stage (mostly at the proerythroblastic stage). (C) CD71⁺ cells (purified by CD71 magnetic column selection). In control spleens, erythroid cells at several maturation stages predominate. (D) CD71⁺ cells from β₁^Δ/Δ spleens are represented mainly by early stages of erythroid cells with fewer more mature erythroid cells (shown by arrows). (E) Smears from R1 (CD7^hi/TER119^lo) cells sorted by FACS. (F) R1 cells from β₁^Δ/Δ. (G) Smears from R2 cells (CD7^hi/TER119^hi) sorted from normal spleens at day 4 after PHZ. Populations of erythroblasts at intermediate maturation stages predominate. (H) Smears of R2-sorted cells from β₁^Δ/Δ spleens at day 4 after PHZ. Fewer later erythroblasts and many large reticulocytes are present. Smears were made using a Shandon cytospin and, after staining, were mounted with distilled water. Photographs were taken at room temperature using a Nikon Coolpix 995 digital camera mounted to the ocular of an Olympus BHT-2 microscope. Magnification bars are inserted. Distilled water was used to mount the cytospins. Images were uploaded into a computer, and Adobe Photoshop was used to correct brightness and contrast.