Methylation patterns at the hypervariable X-chromosome locus DXS255 (M27 beta): correlation with X-inactivation status.
Methylation patterns surrounding a hypervariable X-chromosome locus, DXS255, have been analyzed with the restriction enzyme MspI and its methylation-sensitive isoschizomer HpaII. HpaII sites flanking the hypervariable region were found to be methylated on 41 active X chromosomes and unmethylated on 11 inactive X chromosomes present in a range of male, female, and hybrid cells and tissues. This differential methylation pattern coupled with the previously described high level (greater than 90%) of heterozygosity at the DXS255 locus can therefore be applied to determine the inactivation status of X chromosomes in females heterozygous for X-linked disease and in tumor clonality studies.
Division of Genetics, MRC Radiobiology Unit, Chilton, Didcot, Oxon, England.
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Y
Boyd
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Fraser
D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism*; D004303:Dosage Compensation, Genetic; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D008745:Methylation; D015183:Restriction Mapping; D014178:Translocation, Genetic; D014960:X Chromosome
D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific