title: The bovine IGF2 gene is differentially methylated in oocyte and sperm DNA.
abstract: 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.
authors.affiliation: Department of Biotechnology, Institute for Animal Breeding, Hoeltystrasse 10, D-31535 Neustadt-Mariensee, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Gebert
authors.forename: Christine
authors.initials: C
authors.lastname: Wrenzycki
authors.forename: Doris
authors.initials: D
authors.lastname: Herrmann
authors.forename: Daniela
authors.initials: D
authors.lastname: Gröger
authors.forename: Richard
authors.initials: R
authors.lastname: Reinhardt
authors.forename: Petra
authors.initials: P
authors.lastname: Hajkova
authors.forename: Andrea
authors.initials: A
authors.lastname: Lucas-Hahn
authors.forename: Joseph
authors.initials: J
authors.lastname: Carnwath
authors.forename: Hans
authors.initials: H
authors.lastname: Lehrach
authors.forename: Heiner
authors.initials: H
authors.lastname: Niemann
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002417:Cattle; D018899:CpG Islands; D004247:DNA / Q000378:metabolism; D019175:DNA Methylation; D005091:Exons; D005260:Female; D005786:Gene Expression Regulation; D007335:Insulin-Like Growth Factor II / Q000235:genetics* / Q000378:metabolism; D007438:Introns; D008297:Male; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism*
chemical_list: D020121:5' Untranslated Regions; D007335:Insulin-Like Growth Factor II; D004247:DNA