The Polycomb Group Protein Suz12 Is Required for Embryonic Stem Cell Differentiation

Polycomb group (PcG) proteins form multiprotein complexes, called Polycomb repressive complexes (PRCs). PRC2 contains the PcG proteins EZH2, SUZ12, and EED and represses transcription through methylation of lysine (K) 27 of histone H3 (H3). Suz12 is essential for PRC2 activity and its inactivation results in early lethality of mouse embryos. Total RNA was extracted independently from three WT and three Suz12 KO ES cell clones. RNA was quantified, and equal amounts fromthe three Suz12 WT and the three Suz12 KO samples were pooled into one sample to reduce the experimental variation. Targets for microarray hybridization were synthesized according to the supplier’s instructions (Affymetrix). Hybridization, washing, staining, scanning, and data analysis were performed at the Affymetrix microarray unit at the Institute of Molecular Oncology of the Italian Foundation for Cancer Research-European Institute of Oncology campus, Milan, Italy, according to the manufacturer’s instructions.