A potentially critical Hpa II site of the X chromosome-linked PGK1 gene is unmethylated prior to the onset of meiosis of human oogenic cells.
Hpa II site H8 is in the CpG-rich 5' untranslated region of the human X chromosome-linked gene for phosphoglycerate kinase 1 (PGK1). It is the only Hpa II site in the CpG "island" whose methylation pattern is perfectly correlated with transcriptional silence of this gene. We measured DNA methylation at site H8 in fetal oogonia and oocytes and found, using a quantitative assay based on the polymerase chain reaction, that purified germ cells isolated by micromanipulation were unmethylated in 47-day to 110-day fetuses, whereas ovaries depleted of germ cells and non-ovary tissues were methylated. We conclude that site H8 is unmethylated in germ cells prior to the onset of meiosis and reactivation of the X chromosome.
Department of Biology, Beckman Research Institute, City of Hope Medical Center, Durate, CA 91010.
J
J
Singer-Sam
L
L
Goldstein
A
A
Dai
S M
SM
Gartler
A D
AD
Riggs
D001483:Base Sequence; D004247:DNA / Q000378:metabolism; D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D005786:Gene Expression Regulation; D005796:Genes; D005854:Germ Cells / Q000737:chemistry; D005865:Gestational Age; D006801:Humans; D008540:Meiosis; D008745:Methylation; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D009866:Oogenesis; D010735:Phosphoglycerate Kinase / Q000235:genetics*; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012732:Sex Determination Analysis; D014960:X Chromosome / Q000502:physiology*
D009841:Oligonucleotides; D004247:DNA; D010735:Phosphoglycerate Kinase; D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific