H4K20 trimethylation (H4K20me3) at the X centromere in two human cell lines and one of the mouse-human somatic cell hybrids.

<p>Each number across the schematic representation of the centromere is a genomic site that was interrogated by ChIP-PCR. Control regions, including GAPDH, AFM and X-linked ZXDA are also included. The bar graph shows relative enrichment for H3K27 methylation (n = 3 with SD) calculated as percentage of input.</p

H3K9me2 enrichment at X centromeres in human cell lines and mouse-human hybrids.

<p>The schematic shows the structure of the X centromere. Each number along the centromere represents a genomic site or control region that was interrogated by ChIP-PCR with a specific histone antibody. Each bar graph shows relative enrichment for each histone modification (n≥3 with SD). Control regions, including GAPDH, AFM and X-linked ZXDA are also included. The bar graph shows enrichment calculated as percentage of input.</p

H3K27 mono-methylation (H3K27me1) at the X centromere in human cells and mouse-human somatic cell hybrids.

<p>Each number across the schematic representation of the centromere is a genomic site that was interrogated by ChIP-PCR. Control regions, including GAPDH, AFM and X-linked ZXDA are also included. The bar graph shows relative enrichment for H3K27 methylation (n = 3 with SD) calculated as percentage of input.</p

Comparision of histone modifications across a normal and deleted version of the same X centromere.

<p>The schematics at the top show the structure of the normal <i>(A)</i> and partially deleted <i>(B)</i> X centromere. Each chromosome is contained in a human-hamster cell line. The numbers along the centromere represents genomic sites interrogated by ChIP-PCR with a specific histone antibody. The line plots shows average relative enrichment for each histone modification across the centromere region (n = 3 with SD). Control regions, including GAPDH and and X-linked ZXDA are also included. The bar graph shows relative enrichment for H3K27 methylation (n = 3 with SD) calculated as percentage of input. Asterisks indicate statistically significant differences in enrichment for a modification at a particular site between the normal X and deleted X as determined by a Student's t-test (<i>p</i><0.05).</p

CENP-A mapping on X alpha satellite (DXZ1) on normal and partially deleted X chromosomes in a human-hamster somatic cell hybrid.

<p><i>(A)</i> Schematic of the genomic structure of the X centromeres s of the normal X chromosome in the human:hamster cell line HTM18TC8 and of its 2.7 Mb minichromosome derivative retained in the hamster somatic cell hybrid FA3Wg8-4. <i>(B)</i> IF-FISH on two representative chromatin fibers from the normal X chromosome showing that hamster Cenp-A (red) was localized to a portion of DXZ1 (green), and asymmetrically distributed. Each fiber shown represents an independent experiment. Arrowed lines denote Cenp-A staining (red). Scale bar is 10 microns. <i>(C)</i> IF-FISH on two representative chromatin fibers from the truncated X chromosome showed that CENP-A remained asymmetrically distributed on DXZ1. Each fiber shown represents an independent experiment. Scale bar is 5 microns. <i>(D)</i> Genomic sizes of CENP-A binding domains (gray) and DXZ1 arrays (black) on the normal X before and after partial centromere deletion. N = 15 fibers for normal X and n = 20 fibers for deleted X. The asterisk indicates that reduction in CENP-A array size on the deleted X is statisically significant as determined by a Student's t-test (<i>p</i> = 0.01).</p

Cell lines included in the study.

<p>Cell lines included in the study.</p

H3K27 trimethylation (H3K27me3) at the X centromere in human cells and mouse-human somatic cell hybrids.

<p>Each number across the schematic representation of the centromere is a genomic site that was interrogated by ChIP-PCR. The bar graph shows relative enrichment for H3K27 methylation (n = 3 with SD). Control regions, including GAPDH, AFM and X-linked ZXDA are also included. The bar graph shows relative enrichment for H3K27 methylation (n = 3 with SD) calculated as percentage of input.</p

Primer sets used for ChIP-PCR.

<p>Primer sets used for ChIP-PCR.</p