Impacts of SUMO deficiency in different zebrafish transgenic lines. (A-F) Knock-down SUMOs, Ubc9, or overexpression of Ubc9 (C93A) results in an increase of EGFP in Tg(mpo:EGFP) embryos (A-C), and no such changes are observed in Tg(lyz:EGFP) embryos (D-F) at 28 hpf. Sibling controls and embryos injected with SUMO1-SUMO2-SUMO3 MOs (A and D), Ubc9 (C93A) mRNA (B and E), and Ubc9 MO (C and F) of Tg(mpo:EGFP) or Tg(lyz:EGFP), respectively. (G-J) MPCs undergo myelopoiesis in SUMO-deficient embryos. SUMO deficiency leads to a down-regulation of EGFP resulting from a decreased number of EGFP⁺ cells (10.45% ± 0.636%, n = 150) compared with that of sibling control (17.8% ± 0.283%, n = 140) in Tg(gata1:EGFP) at 22 hpf (G-H). Insets are the amplified views of corresponding ICM. **P < .01. (I-J) Myeloperoxidase staining of sorted EGFP⁺ cells from ICM of sibling controls (I) and SUMO-deficient embryos (J) of Tg(gata1:EGFP) at 22 hpf. Arrows indicate mpo⁺ cells.