Figure 6

The overexpression of C/ebpα ameliorates expansive myelopoiesis in pten- deficient embryos. (A) The expression level of cebpa was negatively related to the number of myeloid cells. Real-time quantitative PCR of cebpa in EGFP-positive myeloid cells from pten−/−;lyz:EGFP and control embryos was performed every 6 hours from 72 to 102 hpf (solid line and left Y-axis). The lyz- positive myeloid cells in each embryo were counted via the whole-mount in situ hybridization analyses of embryos at 72 to 102 hpf (dashed line and right Y-axis). The indicated value is the ratio of pten−/− to control myeloid cells. (B-E) Whole-mount in situ hybridization analyses for lyz in embryos injected with in vitro- synthesized control (B and C) or cebpa (D and E) mRNA at the one-cell stage. The overexpression of cebpa mRNA largely rescues expansive myelopoiesis in pten−/− embryos. The red arrowheads indicate expansive myelopoiesis in the mock-injected pten−/− embryos and the decrease in myeloid cells in the cebpa- injected pten−/− embryos. (F-I) Sudan Black staining of neutrophils in embryos injected with control (F and H) or cebpa (G and I) mRNA. The red arrowheads indicate neutrophils in the CHT. (J and K) Quantification of myeloid cells in each embryo (B-E and F-I). The data shown are the means ± SEM of at least 30 embryos; *p < 0.05, **p < 0.01, ***p < 0.001 versus the corresponding controls. Scale bar: 100 um.