title: HP1γ links histone methylation marks to meiotic synapsis in mice.
abstract: During meiosis, specific histone modifications at pericentric heterochromatin (PCH), especially histone H3 tri- and dimethylation at lysine 9 (H3K9me3 and H3K9me2, respectively), are required for proper chromosome interactions. However, the molecular mechanism by which H3K9 methylation mediates the synapsis is not yet understood. We have generated a Cbx3-deficient mouse line and performed comparative analysis on Suv39h1/h2-, G9a- and Cbx3-deficient spermatocytes. This study revealed that H3K9me2 at PCH depended on Suv39h1/h2-mediated H3K9me3 and its recognition by the Cbx3 gene product HP1γ. We further found that centromere clustering and synapsis were commonly affected in G9a- and Cbx3-deficient spermatocytes. These genetic observations suggest that HP1γ/G9a-dependent PCH-mediated centromere clustering is an axis for proper chromosome interactions during meiotic prophase. We propose that the role of the HP1γ/G9a axis is to retain centromeric regions of unpaired homologous chromosomes in close alignment and facilitate progression of their pairing in early meiotic prophase. This study also reveals considerable plasticity in the interplay between different histone modifications and suggests that such stepwise and dynamic epigenetic modifications may play a pivotal role in meiosis.
authors: RIKEN Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
authors: Yuki
authors: Y
authors: Takada
authors: Chie
authors: C
authors: Naruse
authors: Yael
authors: Y
authors: Costa
authors: Takayuki
authors: T
authors: Shirakawa
authors: Makoto
authors: M
authors: Tachibana
authors: Jafar
authors: J
authors: Sharif
authors: Fuyuko
authors: F
authors: Kezuka-Shiotani
authors: Dai
authors: D
authors: Kakiuchi
authors: Hiroshi
authors: H
authors: Masumoto
authors: Yo-ichi
authors: Y
authors: Shinkai
authors: Kazuyuki
authors: K
authors: Ohbo
authors: Antoine H F M
authors: AH
authors: Peters
authors: James M A
authors: JM
authors: Turner
authors: Masahide
authors: M
authors: Asano
authors: Haruhiko
authors: H
authors: Koseki
mesh_terms: D000818:Animals; D002503:Centromere / Q000648:ultrastructure; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics* / Q000502:physiology; D023902:Chromosome Pairing; D044127:Epigenesis, Genetic; D005260:Female; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics* / Q000502:physiology; D006657:Histones / Q000737:chemistry*; D008297:Male; D008540:Meiosis; D008745:Methylation; D051379:Mice; D018345:Mice, Knockout; D008856:Microscopy, Fluorescence / Q000379:methods; D008957:Models, Genetic; D013090:Spermatocytes / Q000166:cytology
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D000090266:Chromobox Protein Homolog 5; C533711:G9a protein, mouse; D011495:Histone-Lysine N-Methyltransferase