Figure 2

Definitive hematopoiesis is impaired in prpf31^−/−zebrafish.A, bright field observation showed morphological abnormalities in prpf31^−/− zebrafish at 3 dpf. WISH manifested the expression of HSPC markers runx1 and cmyb were noticeably reduced and rescue of cmyb expression after prpf31 mRNA injection. Lateral views. B, expression of the myelocyte markers lyz, l-plastin, and mpx by WISH, and staining signal of Sudan black B labeled neutrophils were significantly decreased in the CHT of prpf31^−/− zebrafish at 3 dpf. Lateral views. C, expression of the erythrocyte markers hbae1.1, hbae3, and hbbe1 were almost undetectable in the CHT of prpf31^−/− zebrafish at 4 dpf, although there was only slightly decrease compared with siblings at 3 dpf by WISH. Lateral views. D, expression of the early T cell marker rag1 was almost completely absent in the thymus of prpf31^−/− zebrafish at 3 dpf by WISH. Lateral and dorsal views. Black arrows denote the CHT region. Red arrows denote the thymus region. The number of embryos with similar gene expression patterns among all embryos examined was shown at the bottom right of each panel. The scale bars represent 250 μm. E, quantification of mRNA signals of prpf31^−/− zebrafish and siblings detected by WISH in (A–D). The total number of embryos examined was indicated below each column. Mean ± SD; unpaired two-tailed t test; ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001; ns, not significant. CHT, caudal hematopoietic tissue; dpf, days postfertilization; hpf, hours postfertilization; HSPC, hematopoietic stem and progenitor cell; PRPF, pre-mRNA processing factor; WISH, whole-mount in situ hybridization.