title: Antisense noncoding RNA promoter regulates the timing of de novo methylation of an imprinting control region.
abstract: Epigenetic marks at cis acting imprinting control regions (ICRs) regulate parent of origin-specific expression of multiple genes in imprinted gene clusters. Epigenetic marks are acquired during gametogenesis and maintained faithfully thereafter. However, the mechanism by which differential epigenetic marks are established and maintained at ICRs is currently unclear. By using Kcnq1 ICR as a model system, we have investigated the functional role of genetic signatures in the acquisition and maintenance of epigenetic marks. Kcnq1 ICR is methylated on the maternal chromosome but remains unmethylated on the paternal chromosome. Here, we show that a paternal allele of Kcnq1 ICR lacking the Kcnq1ot1 promoter remains unmethylated during spermatogenesis; however, it becomes methylated specifically during pre-implantation development. Analysis of the chromatin structure at the paternal ICR in spermatogenic cells and in E13.5 embryonic tissues revealed that the ICRs of both wild type and mutant mice are enriched with H3K4me2 in spermatiogenic cells of the testicular compartment, but the mutant ICR lost H3K4me2 specifically in epididymal sperm and an increase in repressive marks was observed in embryonic tissues. Interestingly, we also detected a decrease in nucleosomal histone levels at the mutant ICR in comparison to the wild-type ICR in epididymal sperm. Taken together, these observations suggest that the Kcnq1ot1 promoter plays a critical role in establishing an epigenetic memory in the male germline by ensuring that the paternal allele remains in an unmethylated state during pre-implantation development.
authors: Uppsala SciLife Laboratory, Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Dag HammarskjöldsVäg 20, S75185, Uppsala University, Uppsala, Sweden.
authors: Natalia
authors: N
authors: Guseva
authors: Tanmoy
authors: T
authors: Mondal
authors: Chandrasekhar
authors: C
authors: Kanduri
mesh_terms: D000818:Animals; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics*; D004622:Embryo, Mammalian / Q000378:metabolism; D047108:Embryonic Development / Q000235:genetics; D005260:Female; D018392:Genomic Imprinting / Q000235:genetics*; D006657:Histones / Q000378:metabolism; D051657:KCNQ1 Potassium Channel / Q000235:genetics; D008239:Lysine / Q000378:metabolism; D008297:Male; D051379:Mice; D009154:Mutation / Q000235:genetics; D009707:Nucleosomes / Q000378:metabolism; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D016372:RNA, Antisense / Q000235:genetics* / Q000378:metabolism; D022661:RNA, Untranslated / Q000235:genetics* / Q000378:metabolism; D017384:Sequence Deletion / Q000235:genetics; D013091:Spermatogenesis / Q000235:genetics; D013737:Testis / Q000166:cytology / Q000378:metabolism; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism
chemical_list: C501971:Cxxc1 protein, mouse; D006657:Histones; D051657:KCNQ1 Potassium Channel; C496910:Kcnq1 protein, mouse; D009707:Nucleosomes; D016372:RNA, Antisense; D022661:RNA, Untranslated; D015534:Trans-Activators; D008239:Lysine