(A) o-dianisidine staining of embryos injected with GFP mRNA (a, a′), hTRIB2 anti-sense mRNA (b, b′) or hTRIB2 mRNA (c, c′) was performed at 48 hpf. Hemoglobin staining (red arrows) was significantly increased in hTRIB2 mRNA–injected embryos. (B) Whole-mount in situ hybridizations with antisense βe1-globin (bE1), αA1-globin (aA1) and βA1-globin (bA1). The images weretaken from a lateral view, with anterior to the left and dorsal to the top. Embryos were stained under the same conditions and for the same period of time to ensure comparable sensitivity. Multiple embryos were injected and analyzed, and statistical results are shown in (C). The number of embryos with a positive signal divided by the number of embryos injected is shown at the top of each bar. Two independent experiments were performed, and one representative result is shown. (D) Semi-quantitative RT-PCR for differential expression of zebrafish βe1-globin (bE1), αA1-globin (aA1) and βA1-globin (bA1), and β-actin in GFP mRNA, hTRIB2 anti-sense mRNA and hTRIB2 mRNA–injected embryos at 22 hpf. Similar results were obtained from three experiments using separate embryos injected with GFP mRNA, hTRIB2 anti-sense mRNA and hTRIB2 mRNA. Scale bars: 100 μm in (A,B).