title: GSE is a maternal factor involved in active DNA demethylation in zygotes.
abstract: After fertilization, the sperm and oocyte genomes undergo extensive epigenetic reprogramming to form a totipotent zygote. The dynamic epigenetic changes during early embryo development primarily involve DNA methylation and demethylation. We have previously identified Gse (gonad-specific expression gene) to be expressed specifically in germ cells and early embryos. Its encoded protein GSE is predominantly localized in the nuclei of cells from the zygote to blastocyst stages, suggesting possible roles in the epigenetic changes occurring during early embryo development. Here, we report the involvement of GSE in epigenetic reprogramming of the paternal genome during mouse zygote development. Preferential binding of GSE to the paternal chromatin was observed from pronuclear stage 2 (PN2) onward. A knockdown of GSE by antisense RNA in oocytes produced no apparent effect on the first and second cell cycles in preimplantation embryos, but caused a significant reduction in the loss of 5-methylcytosine (5mC) and the accumulation of 5-hydroxymethylcytosine (5hmC) in the paternal pronucleus. Furthermore, DNA methylation levels in CpG sites of LINE1 transposable elements, Lemd1, Nanog and the upstream regulatory region of the Oct4 (also known as Pou5f1) gene were clearly increased in GSE-knockdown zygotes at mid-pronuclear stages (PN3-4), but the imprinted H19-differential methylated region was not affected. Importantly, DNA immunoprecipitation of 5mC and 5hmC also indicates that knockdown of GSE in zygotes resulted in a significant reduction of the conversion of 5mC to 5hmC on LINE1. Therefore, our results suggest an important role of maternal GSE for mediating active DNA demethylation in the zygote.
authors.affiliation: Division of Biological Science, Kinki University Graduate School of Biology-Oriented Science and Technology, Kinokawa, Wakayama, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hatanaka
authors.forename: Natsumi
authors.initials: N
authors.lastname: Shimizu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nishikawa
authors.forename: Mikiko
authors.initials: M
authors.lastname: Tokoro
authors.forename: Seung-Wook
authors.initials: SW
authors.lastname: Shin
authors.forename: Takuji
authors.initials: T
authors.lastname: Nishihara
authors.forename: Tomoko
authors.initials: T
authors.lastname: Amano
authors.forename: Masayuki
authors.initials: M
authors.lastname: Anzai
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kato
authors.forename: Tasuku
authors.initials: T
authors.lastname: Mitani
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hosoi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kishigami
authors.forename: Kazuya
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D044503:5-Methylcytosine / Q000378:metabolism / Q000031:analogs & derivatives; D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D003596:Cytosine / Q000031:analogs & derivatives / Q000378:metabolism; D019175:DNA Methylation; D004622:Embryo, Mammalian; D047108:Embryonic Development; D044127:Epigenesis, Genetic; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008297:Male; D051379:Mice; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011506:Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012737:Sex Factors; D015053:Zygote / Q000166:cytology / Q000378:metabolism*
chemical_list: D044503:5-Methylcytosine; D002843:Chromatin; D003596:Cytosine; D018398:Homeodomain Proteins; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; D011506:Proteins; D034741:RNA, Small Interfering; C515280:Stpg4 protein, mouse; C475540:Nanog protein, mouse; C494174:Pou5f1 protein, mouse; C011865:5-hydroxymethylcytosine
references.citation: Dev Biol. 2002 Jan 1;241(1):172-82
references.pmid: 11784103
references.citation: Mol Cell. 2006 Dec 28;24(6):977-84
references.pmid: 17189198
references.citation: EMBO J. 2010 Jun 2;29(11):1877-88
references.pmid: 20442707
references.citation: Trends Genet. 2012 Apr;28(4):164-74
references.pmid: 22386917
references.citation: Nucleic Acids Res. 2010 Jun;38(11):e125
references.pmid: 20371518
references.citation: J Reprod Dev. 2010 Dec;56(6):655-63
references.pmid: 20814167
references.citation: Biol Reprod. 2009 Mar;80(3):473-83
references.pmid: 19020302
references.citation: PLoS One. 2010 Jan 26;5(1):e8888
references.pmid: 20126651
references.citation: Mech Dev. 2005 Sep;122(9):1008-22
references.pmid: 15922569
references.citation: J Reprod Dev. 2006 Jun;52(3):429-38
references.pmid: 16571911
references.citation: Nature. 2012 Mar 28;484(7394):339-44
references.pmid: 22456710
references.citation: J Reprod Dev. 2008 Jun;54(3):192-7
references.pmid: 18360097
references.citation: Cell Res. 2013 Jan;23(1):6-9
references.pmid: 22868271
references.citation: Trends Genet. 2011 May;27(5):177-85
references.pmid: 21497937
references.citation: Nature. 2011 Sep 04;477(7366):606-10
references.pmid: 21892189
references.citation: Mol Reprod Dev. 2009 Apr;76(4):342-50
references.pmid: 18932201
references.citation: Mol Reprod Dev. 2008 Jul;75(7):1104-8
references.pmid: 18324673
references.citation: Nat Genet. 1995 Apr;9(4):407-13
references.pmid: 7795647
references.citation: J Reprod Dev. 2006 Oct;52(5):601-6
references.pmid: 16807506
references.citation: Nature. 2012 Jun 03;486(7403):415-9
references.pmid: 22722204
references.citation: Nat Rev Mol Cell Biol. 2009 Aug;10(8):526-37
references.pmid: 19603040
references.citation: Int J Dev Biol. 2006;50(5):455-61
references.pmid: 16586346
references.citation: J Reprod Dev. 2009 Jun;55(3):316-26
references.pmid: 19325216
references.citation: Nature. 2012 Jul 04;487(7405):43-5
references.pmid: 22763548
references.citation: Hum Mol Genet. 2005 Apr 15;14 Spec No 1:R47-58
references.pmid: 15809273
references.citation: Nat Rev Genet. 2008 Feb;9(2):129-40
references.pmid: 18197165
references.citation: Nature. 2010 Jan 28;463(7280):554-8
references.pmid: 20054296
references.citation: Methods Enzymol. 1993;225:153-64
references.pmid: 8231853
references.citation: Proc Natl Acad Sci U S A. 2011 Mar 1;108(9):3642-7
references.pmid: 21321204
references.citation: Nat Commun. 2011;2:241
references.pmid: 21407207
references.citation: Nat Cell Biol. 2007 Jan;9(1):64-71
references.pmid: 17143267
references.citation: J Reprod Dev. 2010 Dec;56(6):607-15
references.pmid: 20710121
references.citation: Development. 2012 Jan;139(1):15-31
references.pmid: 22147951
references.citation: Science. 2010 Jul 2;329(5987):78-82
references.pmid: 20595612