Figure 2.

STAT3 is phosphorylated by LIF-dependent and -independent pathways during preimplantation mouse development. Immunostaining of (pY705)-STAT3 in Cdh1^mat−/− and Lif^−/− four-cell embryos (A), (pY705)-STAT3 in Lif^+/+ and Lif^−/− morulas and early blastocysts (B), and (pY705)-STAT3 in control embryos and embryos treated with neutralizing antibodies against IFN-γ and IL-6 cytokines (C). Bar, 20 μm. (D) Bar graph showing the average of pSTAT3-positive cells in controls and in embryos treated with anti-IFN-γ and anti-IL-6 antibodies.