Developmental mechanism and origin of dyserythropoiesis. (A-B) WISH analyses of αE1-globin in the indicated transgenic embryos at 75 hpf. The star, red arrow, and arrowheads indicate the increased number of erythrocytes expressing αE1-globin transcripts within the embryonic vasculature. (C-J) Time course of WISH analyses of scl in the transgenic embryos at indicated developmental stages. Red arrows and arrowheads indicate the increased scl⁺ HSPCs in the CHT and bilateral PDs. (K) Two-color WISH of EGFP (black color) and scl (red color) transcripts in the transgenic embryos at 32 hpf. (K-L) Fast red labeling of scl (RITC filter) is shown to the right. The red and black arrows indicate the colocalization of scl and EGFP.