title: Asymmetry in histone H3 variants and lysine methylation between paternal and maternal chromatin of the early mouse zygote.
abstract: In mammalian fertilization, the paternal genome is delivered to the secondary oocyte by sperm with protamine compacted DNA, while the maternal genome is arrested in meiotic metaphase II. Thus, at the beginning of fertilization, the two gametic chromatin sets are strikingly different. We elaborate on this contrast by reporting asymmetry for histone H3 type in the pre-S-phase zygote when male chromatin is virtually devoid of histone H3.1/3.2. Localization of the histone H3.3/H4 assembly factor Hira with the paternal chromatin indicates the presence of histone H3.3. In conjunction with this, we performed a systematic immunofluorescence analysis of histone N-tail methylations at position H3K4, H3K9, H3K27 and H4K20 up to the young pronucleus stage and show that asymmetries reported earlier are systematic for virtually all di- and tri-methylations but not for mono-methylation of H3K4 and H4K20, the only marks studied present in the early male pronucleus. For H4K20 the expanding male chromatin is rapidly mono-methylated. This coincides with the formation of maternally derived nucleosomes, a process which is observed as early as sperm chromatin decondensation occurs. Absence of tri-methylated H3K9, tri-methylated H4K20 and presence of loosely anchored HP1-beta combined with the homogenous presence of mono-methylated H4K20 suggests the absence of a division of the paternal chromatin in eu- and heterochromatin. In summary the male, in contrast to female G1 chromatin, is uniform and contains predominantly histone H3.3 as histone H3 variant.
authors.affiliation: Department of Obstetrics and Gynaecology, University Medical Centre St Radboud, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Godfried W
authors.initials: GW
authors.lastname: van der Heijden
authors.forename: Jürgen W
authors.initials: JW
authors.lastname: Dieker
authors.forename: Alwin A H A
authors.initials: AA
authors.lastname: Derijck
authors.forename: Sylviane
authors.initials: S
authors.lastname: Muller
authors.forename: Jo H M
authors.initials: JH
authors.lastname: Berden
authors.forename: Didi D M
authors.initials: DD
authors.lastname: Braat
authors.forename: Johan
authors.initials: J
authors.lastname: van der Vlag
authors.forename: Peter
authors.initials: P
authors.lastname: de Boer
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D044127:Epigenesis, Genetic; D018604:Epitope Mapping; D005260:Female; D005306:Fertilization; D005455:Fluorescent Antibody Technique; D014644:Genetic Variation; D056488:Histone Chaperones; D006657:Histones / Q000737:chemistry* / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D008239:Lysine / Q000737:chemistry; D008297:Male; D008745:Methylation; D051379:Mice; D008808:Mice, Inbred CBA; D009707:Nucleosomes / Q000378:metabolism; D011247:Pregnancy; D011479:Protamines / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D015053:Zygote / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D002843:Chromatin; C484187:Hira protein, mouse; D056488:Histone Chaperones; D006657:Histones; D009707:Nucleosomes; D011479:Protamines; D014157:Transcription Factors; D008239:Lysine