Xsl function is required for differentiation of primitive erythrocytes but not leukocytes. (A) Number of erythrocytes and leukocytes in tadpoles that had been injected with Xsl MOs (▪) or with DN-Kit RNA (▦) expressed as a percentage of cell number in control embryos (□). Error bars show the SEM. Pooled results from 3 independent experiments are presented. (B-D) Wright-Giemsa stained cytospins of representative samples from control (B), Xsl MO- (C), and DN-kit– (D) injected embryos; e indicates erythrocyte; l, leukocyte.