<i>hoxd4a</i> knockdown disrupts primitive hematopoiesis and is highly specific.

<p><i>In situ</i> hybridization revealing expression at 13 hpf of erythroid lineage markers <i>gata1</i> (A,C,E) and <i>β embryonic globin 1</i> (<i>hbbe1</i>) (B,D,F). (A,B) Normal expression of <i>gata1</i> and <i>hbbe1</i> in the LPM. (C,D) Expression of <i>gata1</i> and <i>hbbe1</i> is strongly down-regulated in <i>hoxd4a</i> morphants, but rescued by co-injection of capped mRNA for <i>hoxd4a</i> (E,F). All embryos have been flat-mounted and are shown in dorsal view. Anterior is to the left. Ratios in the bottom left corner of all panels indicate the number of embryos showing the presented phenotype. ctrl, embryos injected with a non-specific morpholino. MO, embryos injected with the anti-<i>hoxd4a</i> morpholino. <i>hoxd4a</i> mRNA, embryos simultaneously injected with the anti-<i>hoxd4a</i> MO plus capped mRNA for <i>hoxd4a</i>. Scale bars equal 100 µm. All images are at the same magnification.