Xce haplotypes show modified methylation in a region of the active X chromosome lying 3' to Xist.
During early mammalian embryogenesis, one of the two X chromosomes in somatic cells of the female becomes inactivated through a process that is thought to depend on a unique initiator region, the X-chromosome inactivation center (Xic). The recently characterized Xist sequence (X-inactive-specific transcript) is thought to be a possible candidate for Xic. In mice a further genetic element, the X chromosome-controlling element (Xce), is also known to influence the choice of which of the two X chromosomes is inactivated. We report that a region of the mouse X chromosome lying 15 kb distal to Xist contains several sites that show hypermethylation specifically associated with the active X chromosome. Analysis of this region in various Xce strains has revealed a correlation between the strength of the Xce allele carried and the methylation status of this region. We propose that such a region could be involved in the initial stages of the inactivation process and in particular in the choice of which of the two X chromosomes present in a female cell will be inactivated.
Courtier
B
B
Unité de Génétique Moléculaire Murine, Institut Pasteur, Paris, France.
Heard
E
E
Avner
P
P
D000818:Animals; D004247:DNA / Q000378:metabolism; D015280:DNA Restriction-Modification Enzymes / Q000378:metabolism*; D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D004303:Dosage Compensation, Genetic; D005260:Female; D014644:Genetic Variation; D006239:Haplotypes; D008297:Male; D008745:Methylation; D051379:Mice; D008815:Mice, Inbred Strains; D010735:Phosphoglycerate Kinase / Q000235:genetics; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D015183:Restriction Mapping; D012733:Sex Differentiation / Q000235:genetics; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics*; D014960:X Chromosome / Q000235:genetics*
D015280:DNA Restriction-Modification Enzymes; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014157:Transcription Factors; C077885:XIST non-coding RNA; D004247:DNA; D010735:Phosphoglycerate Kinase; D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific; C029792:GTCGAC-specific type II deoxyribonucleases