title: Maternal imprinting during mouse oocyte growth in vivo and in vitro.
abstract: Epigenetic regulation of gene expression is critical for oogenesis in mammals. In this study, a simple and efficient method was used to obtain the oocytes from cultured fetal mouse ovaries of 12.5dpc. The methylation pattern of these oocytes was examined. The results showed that the establishment of imprinting of Igf2r and Peg3 in oocytes derived from cultured fetal mouse germ cells in vitro follows a slower time course than that of oocytes in vivo. However, oocytes in vitro and in vivo share similar methylation patterns. Igf2r was gradually de novo methylated, and the methylation covers 80% CpG sites in oocytes cultured for 28days. However, only 45% of the CpG sites is methylated in Peg3 at the same stage. Furthermore, it demonstrated that the degree of DNA methylation is positively correlated with the size of oocytes in vitro and in vivo, indicating a progressive methylation process during oocyte growth.
authors: Qingdao Agricultural University, China.
authors: Zhenhua
authors: Z
authors: Song
authors: Lingjiang
authors: L
authors: Min
authors: Qingjie
authors: Q
authors: Pan
authors: Qinghua
authors: Q
authors: Shi
authors: Wei
authors: W
authors: Shen
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D019175:DNA Methylation; D005260:Female; D018392:Genomic Imprinting; D006107:Granulosa Cells / Q000502:physiology; D051741:Kruppel-Like Transcription Factors / Q000235:genetics; D051379:Mice; D008815:Mice, Inbred Strains; D009865:Oocytes / Q000254:growth & development*; D009866:Oogenesis / Q000235:genetics*; D017527:Receptor, IGF Type 2 / Q000235:genetics
chemical_list: D051741:Kruppel-Like Transcription Factors; C097901:Peg3 protein, mouse; D017527:Receptor, IGF Type 2