Knockdown of adtrp1 expression disrupts the specification of primitive myelopoiesis during embryogenesis. A–H) Knockdown of adtrp1 expression did not affect the expression levels of gata1 (18 hpf, A, B; 24 hpf, C, D) and hbae1 (18 hpf, E, F; 26 hpf, G, H)—markers for erythropoiesis during primitive hematopoiesis. I–N2) Knockdown of adtrp1 expression reduced the expression level of pu-1 (12 hpf, I, J; 18 hpf, K, L; 24 hpf, M1–N2), a myeloid progenitor marker. O1–R2) Knockdown of adtrp1 expression reduced the expression levels of mpo (26 hpf; O1–P2), a granulocyte marker, and l-plastin (26 hpf; Q1–R2), a monocyte/macrophage cell marker.