Methylation and sequence analysis around Eagi sites: Identification of 28 new CpG islands in XQ24-XQ28

Carla Tribioli, Filippo Tamanini, Cristina Patrosso, Luciano Milanesi, Anna Villa, Rossana Pergolizzi, Elena Maestrini, Stefano Rivella, Silvia Bione, Mita Mancini, Paolo Vezzoni, Daniela Toniolo

Research output: Contribution to journalArticlepeer-review


Thirtytwo probes for CpG islands of the distal long arm of the human X chromosome have been identified. From a genomic library of DNA of the hamster-human cell hybrid X3000.1 digested with the rare cutter restriction enzyme Eagl, 53 different human clones have been isolated and characterized by methylation and sequence analysis. The characteristic pattern of DNA methylation of CpG islands at the 5′ end of genes of the X chromosome has been used to distinguish between Eagl sites in CpG islands versus isolated Eagl sites. The sequence analysis has confirmed and completed the characterization showing that sequences at the 5′ end of known genes were among the clones defined CpG islands and that the non-CpG islands clones were mostly repetitive sequences with a non-methylated or variably methylated Eagl site. Thus, since clones corresponding to repetitive sequences can be easily identified by sequencing, such libraries are a very good source of CpG islands. The methylation analysis of 28 different new probes allows to state that demethylation of CpG islands of the active X and methylation of those on the inactive X chromosome are the general rule. Moreover, the finding, in all instances, of methylation differences between male and female DNA is in very strong support of the notion that most genes of the distal long arm of the X chromosome are subject to X inactivation.

Original languageEnglish
Pages (from-to)727-733
Number of pages7
JournalNucleic Acids Research
Issue number4
Publication statusPublished - Feb 25 1992

ASJC Scopus subject areas

  • Genetics
  • Statistics, Probability and Uncertainty
  • Applied Mathematics
  • Health, Toxicology and Mutagenesis
  • Toxicology
  • Genetics(clinical)


Dive into the research topics of 'Methylation and sequence analysis around Eagi sites: Identification of 28 new CpG islands in XQ24-XQ28'. Together they form a unique fingerprint.

Cite this