Ischemia enhances association of diMeK9-H3, but not diMeK4-H3, with the MOR-1 promoter in CA1. (a) ChlP analysis of cross-linked chromatin from the CA1 of control (Ctl) and experimental animals at 12, 24, and 48 h after ischemia immunoprecipitated with antibody to diMeK9-H3 (a Middle and b) or diMeK4-H3 (a Top and b) (Materials and Methods). (a) Representative ethidium bromide-stained agarose gel showing amplification of promoter fragments. Left lanes show ODN length standards. (b) Levels of diMeK9-H3 and diMeK4-H3 at MOR-1 promoter in CA1 were quantified by using real-time PCR. Ct values of immunoprecipitated samples were normalized to the corresponding value for input. Bars represent mean ± SEMs. ∗, P < 0.05; ∗∗, P < 0.01; ∗∗∗, P < 0.001 vs. control (Student's paired t test).