TY - JOUR
T1 - Methylation and sequence analysis around Eagi sites
T2 - Identification of 28 new CpG islands in XQ24-XQ28
AU - Tribioli, Carla
AU - Tamanini, Filippo
AU - Patrosso, Cristina
AU - Milanesi, Luciano
AU - Villa, Anna
AU - Pergolizzi, Rossana
AU - Maestrini, Elena
AU - Rivella, Stefano
AU - Bione, Silvia
AU - Mancini, Mita
AU - Vezzoni, Paolo
AU - Toniolo, Daniela
PY - 1992/2/25
Y1 - 1992/2/25
N2 - 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.
AB - 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.
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M3 - Article
C2 - 1542569
AN - SCOPUS:0026585834
VL - 20
SP - 727
EP - 733
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 4
ER -