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Fig. 2 | Molecular Cytogenetics

Fig. 2

From: Reversing chromatin accessibility differences that distinguish homologous mitotic metaphase chromosomes

Fig. 2

Representative example of differential accessibility (DA) and its reduction with topoisomerase IIα inhibitor ICRF-193. a Metaphase cell showing chromosome 1 homologs hybridized with single copy DNA FISH probe from within RGS7 (2.09 kb). Relative to its homolog, * marks the chromosome with the weaker probe hybridization signal; indicating DA. Inset shows metaphase cell with homologs of interest (boxed). b-c Ladder plots compare effect of topoisomerase IIα inhibitor, ICRF-193, on DA at various concentrations and genomic loci in two lymphoblastoid cell lines. Colored lines connecting two points, pre and post-treatment (x axis), represent different genomic targets as indicated in the key. Frequency of DA to homologous regions is expressed as a percentage (y axis). Greater than two-thirds (dotted line) of the cells analyzed (n = 20–100 cells, μ = 43 cells/per target) in pre-treatment control showed DA. b In cell line GM06326, with the exception of HERC2, DA was significantly reduced post-treatment (z-score < −2.0, p < 0.05, two-proportion z test) at distinct genomic targets. c These findings were reproduced in a second cell line, GM10958, however in this case, reduction in DA was marginally significant at PMP22:IVS3 and ACR (indicated by *)

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