Histone modification patterns of expressed and repressed hCD2 transgene in the CD2 1.3 variegating transgenic lines. (A) fluorescence-activated cell sorter (FACS) analysis of hCD2 expression on the surface of pre-sorted (green) and sorted (solid black) peripheral T cells. The hCD2 expression profile of non-transgenic T cells is shown in red. Chromosomal location of hCD2 transgene (orange circle) in each transgenic line is shown in the plots: pericentric regions and chromosome arms are shown as a black circle and white ovals respectively. (B) Schematic diagram of hCD2 transgene locus. Note that the 3' regulatory region is oriented in reverse directions in the CD2 1.3B and CD2 1.3A14 transgenic line. Locations of the primers used for chromatin immunoprecipitation (ChIP) assays are indicated with black bars and letters at the bottom. (C) ChIP analysis of histone modifications along the hCD2 transgene in hCD2+ and hCD2- T cells. ChIP was performed with chromatin prepared from sorted hCD2+ or hCD2- T cells from CD2 1.3B (white or black bar) and CD2 1.3A14 (grey bar) transgenics using antibodies against various histone H3 modifications. Enrichment for each modification was determined by qPCR and normalized to 5% input (black asterisks = P < 0.05, red asterisks = P < 0.005). This experiment was repeated three times (error bars = standard deviation). (D) control PCR on ChIP-ed materials using primers against expressed (CD3ε, β-actin) or repressed (IAP) loci.