Methylation Dynamics of Imprinted Genes in Mouse Germ Cells

摘要: DNA methylation differences between maternal and paternal alleles of many imprinted genes are inherited from the male female gametes subsequently maintained during development. However, stages gametogenesis which imprints established have not been well defined. In this study, we used bisulfite sequencing to determine dynamics small nuclear ribonucleoprotein N (Snrpn), insulin-like growth factor 2 receptor (Igf2r), mesoderm-specific transcript (Mest; formerly Peg1), paternally expressed gene 3 (Peg3), H19 fetal liver mRNA (H19). We identified regions in maternally (Snrpn, Mest, Peg3) that were unmethylated sperm but 100% methylated mature oocytes. Igf2r, is allele, was completely within intronic differentially region oocytes sperm. The 5' H19, a gene, examined status Snrpn oocyte maturation. Whereas non-growing mostly unmethylated, mid-size growing had mosaic pattern allelic methylation, full acquisition imprint complete by metaphase II. show gamete-specific patterns germ cells demonstrated on at least one Snrpn, postnatal phase oogenesis. Thus, whereas seem be early (in diploid gonocytes before onset meiosis), late arrested diplotene stage meiosis). These findings raise possibility assisted reproductive technologies involve vitro maturation may result developmental abnormalities due incomplete immature