Cell proliferation is unchanged in MO3 injected embryos. Whole mount immunohistochemistry with mitotic marker anti-phosphohistone H3 shows proliferating cells in developing embryos. UIC (a–c), MO3 (d–f), and control MM-MO3-injected embryos (g–i) embryos at 16 hpf (a, d, g), 24 hpf (b, e, h), and 48 hpf (c, f, i). (j) Quantification of number of proliferating cells in UIC, MO3, and control MM-MO3 injected embryos at 16 and 24 hpf.