Figure 3.

Principal polycomb group proteins in the mouse hippocampus. Western blot depictions here were obtained following multiple exposures. For nuclear and cytosolic fractionation, either three CA3 tissue samples or two hippocampal tissue samples were pooled and run numerous times for each immunoblot. For analysis of whole lysates, lysates were from a single animal. Each column represents one lysate, with each row representing an independent immunoblot and exposure. (A) Western blotting was performed on whole cell lysates of the CA3, whole hippocampus, cerebral cortex, cerebellum, and spleen as well as cytosolic and nuclear fractions of the CA3 and the whole hippocampus to confirm the expression of PcG proteins in the adult brain. Observed molecular weights based on the migration of a protein ladder are given (right). (B) The neuronal expression of the polycomb repressive complex 2 (PRC2) catalytic subunit EZH2 was validated by immunofluorescence, with a similar pattern of expression observed for the PRC2-associated epigenetic histone modification, trimethylation of lysine27 in histone 3. CA, cornu ammonis; CEREB, cerebellum; CTX, cortex; DG, dentate gyrus; H, hilus; trimethyl-H3K27, trimethylated lysine 27 of histone 3; HIPP, hippocampus; HST, Hoechst. Scale, 50 μm.