Suppression of erythroid-lineage factors biklf and gata1 strongly induces ectopic lyz expression in the ICM. (A–P) All embryos are around 24 hpf and lateral view; anterior is left. Morpholinos (biklf MO; 10 ng) were injected into one-cell stage embryos from wild-type or vlad tepes (vlt)/gata1 mutant, and the expression of myeloid markers was examined by whole-mount in situ hybridization; marker is shown at bottom right. Genome DNA was prepared from the stained embryos after taking pictures, and genotyping of vlt was performed. The myeloid markers, pu.1, c/ebp1, runx1 and lyz are expressed in myeloid cells over the yolk (orange arrowheads) (A, E and M). The expression of pu.1, c/ebp1, runx1 and lyz was weakly induced in the ICM (red arrowheads) in vlt embryos or biklf MO-injected embryos. When biklf MO was injected into vlt embryos, the markers (pu.1, c/ebp1, runx1 and lyz) were strongly induced in the ICM (red arrowheads). (Q and R) EGFP expression is detected in myeloid cells (orange arrowheads) in uninjected embryo from Tg(lyz:EGFP)ko02. EGFP expression at 23 hpf stage was significantly induced in the ICM (white arrowheads), when morpholinos (gata1 MO; 10 ng + biklf MO; 10 ng) were injected into one-cell stage embryos of Tg(lyz:EGFP)ko02. (S and T) mRFP expression in the ALPM (orange arrowheads) at 23 hpf stage was slightly increased, when morpholinos (pu.1 MO; 10 ng + c/ebp1 MO; 10 ng) were injected into one-cell stage embryos of Tg(gata1:mRFP)ko05.