The bovine IGF2 gene is differentially methylated in oocyte and sperm DNA

• Published in: Genomics (San Diego, Calif.) Vol. 88; no. 2; pp. 222 - 229
• Main Authors: Gebert, Claudia, Wrenzycki, Christine, Herrmann, Doris, Gröger, Daniela, Reinhardt, Richard, Hajkova, Petra, Lucas-Hahn, Andrea, Carnwath, Joseph, Lehrach, Hans, Niemann, Heiner
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.08.2006; Elsevier
• Subjects: 5' Untranslated Regions - genetics; 5' Untranslated Regions - metabolism; Animals; Biological and medical sciences; Cattle; CpG Islands; Differentially methylated region; DNA - metabolism; DNA Methylation; Exons; Female; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Genes. Genome; Genetics of eukaryotes. Biological and molecular evolution; IGF2; Insulin-Like Growth Factor II - genetics; Insulin-Like Growth Factor II - metabolism; Introns; Male; Models, Genetic; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Oocytes - cytology; Oocytes - metabolism; Sequence Analysis, DNA; Spermatozoa - cytology; Spermatozoa - metabolism; IGF2; Cattle; Differentially methylated region; Bovine; Semen; Genomics; Germinal cell; Insulin like growth factor 2; Vertebrata; Mammalia; Gene; DNA; Artiodactyla; Ungulata; Oocyte
• ISSN: 0888-7543; 1089-8646
• DOI: 10.1016/j.ygeno.2006.03.011

The insulin-like growth factor 2 gene ( IGF2) encodes an essential growth factor and is imprinted in various mammalian species. Differentially methylated regions (DMRs) are often located within CpG islands and are critically involved in the regulation of monoallelic Igf2 expression in the mouse. Only partial sequence information is available for the bovine IGF2 gene and no DMR has currently been identified. The goal of this study was to identify a DMR within the bovine IGF2 gene as a prerequisite for further studies on gene-specific methylation patterns during preimplantation development. Here we describe the sequence analysis of a CpG-rich DNA fragment from the 5′ untranslated region spanning exons and introns 4 and 5 and the identification of a previously unknown DMR in exon 10 of the bovine IGF2 gene. Bisulfite analysis revealed that this DMR is differentially methylated in mature oocytes and sperm. The identification of an intragenic DMR within a developmentally important gene such as the bovine IGF2 gene provides a useful tool to evaluate the methylation patterns of embryos derived in vivo and in vitro. Our study is the first report of a differentially methylated region in a bovine imprinted gene discovered by the analysis of female and male gametes.