Dynamics of splenic erythroid regeneration in response to PHZ and bleeding stress. (A) Schematic illustration of the experiment to generate PHZ- and BLD-induced stress erythropoiesis models. (B-C) Peripheral blood analysis in mice treated with PHZ (B) or BLD (C) at various time points. Triangle indicates the time point chosen for subsequent analyses. (D) Comparison of spleen morphology under normal conditions, PHZ and bleeding (n = 2). (E) Histological examination (using hematoxylin and eosin staining) of spleen tissue from mice under normal, PHZ, and bleeding conditions. (F) Schematic illustration of experiment to analyze single cell transcriptomes. (G) UMAP visualization of pooled scRNA-seq data from normal, PHZ, and bleeding conditions, with annotations of 9 subpopulations. (H) UMAP visualization of 9 annotated subpopulations from normal, PHZ, and bleeding spleen tissues respectively. (I) Dot plot showing feature genes of each annotated subpopulations. HCT, hematocrit; HGB, hemoglobin; NK, natural killer; NT, no treatment.