Maternal Primary Imprinting Is Established at a Specific Time for Each Gene throughout Oocyte Growth

• Published in: The Journal of biological chemistry Vol. 277; no. 7; pp. 5285 - 5289
• Main Authors: Obata, Yayoi, Kono, Tomohiro
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 15.02.2002
• Subjects: Alleles; Animals; Autoantigens - biosynthesis; Cyclin-Dependent Kinase Inhibitor p57; Female; Genomic Imprinting; Igf2r gene; Impact gene; Intracellular Signaling Peptides and Proteins; Kruppel-Like Transcription Factors; Male; Mest gene; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Models, Biological; Mothers; Ndn gene; Nuclear Proteins - biosynthesis; Oocytes - metabolism; Oocytes - physiology; p57KIP2 protein; Peg1 gene; Peg3 gene; Protein Biosynthesis; Protein Kinases; Proteins; Receptor, IGF Type 2 - biosynthesis; Reverse Transcriptase Polymerase Chain Reaction; Ribonucleoproteins - biosynthesis; Ribonucleoproteins, Small Nuclear; snRNP Core Proteins; Snrpn gene; Time Factors; Transcription Factors; Ubiquitin-Protein Ligases; Znf127 gene
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M108586200

Primary imprinting during gametogenesis governs the monoallelic expression/repression of imprinted genes in embryogenesis. Previously, we showed that maternal primary imprinting is disrupted in neonate-derived non-growing oocytes. Here, to investigate precisely when and in what order maternal primary imprinting progresses, we produced parthenogenetic embryos containing one genome from a non-growing or growth-stage oocyte from 1- to 20-day-old mice and one from a fully grown oocyte of adult mice. We used these embryos to analyze the expression of eight imprinted genes: Peg1/Mest , Peg3 , Snrpn , Znf127 , Ndn , Impact , Igf2r , and p57 KIP2 . The results showed that the imprinting signals for each gene were not all imposed together at a specific time during oocyte growth but rather occurred throughout the period from primary to antral follicle stage oocytes. The developmental ability of the constructed parthenogenetic embryos was gradually reduced as the nuclear donor oocytes grew. These studies provide the first insight into the process of primary imprinting during oocyte growth.