title: Poised chromatin and bivalent domains facilitate the mitosis-to-meiosis transition in the male germline.
abstract: BACKGROUND
  The male germline transcriptome changes dramatically during the mitosis-to-meiosis transition to activate late spermatogenesis genes and to transiently suppress genes commonly expressed in somatic lineages and spermatogenesis progenitor cells, termed somatic/progenitor genes.
  
  
  RESULTS
  These changes reflect epigenetic regulation. Induction of late spermatogenesis genes during spermatogenesis is facilitated by poised chromatin established in the stem cell phases of spermatogonia, whereas silencing of somatic/progenitor genes during meiosis and postmeiosis is associated with formation of bivalent domains which also allows the recovery of the somatic/progenitor program after fertilization. Importantly, during spermatogenesis mechanisms of epigenetic regulation on sex chromosomes are different from autosomes: X-linked somatic/progenitor genes are suppressed by meiotic sex chromosome inactivation without deposition of H3K27me3.
  
  
  CONCLUSIONS
  Our results suggest that bivalent H3K27me3 and H3K4me2/3 domains are not limited to developmental promoters (which maintain bivalent domains that are silent throughout the reproductive cycle), but also underlie reversible silencing of somatic/progenitor genes during the mitosis-to-meiosis transition in late spermatogenesis.
authors.affiliation: Division of Reproductive Sciences, Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA.|Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 49229, USA.|Present address: Department of Developmental Biology, Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA.
authors.forename: Ho-Su
authors.initials: HS
authors.lastname: Sin
authors.affiliation: Division of Allergy and Immunology, Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA.|Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 49229, USA.
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Kartashov
authors.affiliation: Division of Reproductive Sciences, Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA.|Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 49229, USA.|Present address: Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA.
authors.forename: Kazuteru
authors.initials: K
authors.lastname: Hasegawa
authors.affiliation: Division of Allergy and Immunology, Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA. artem.barski@cchmc.org.|Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 49229, USA. artem.barski@cchmc.org.
authors.forename: Artem
authors.initials: A
authors.lastname: Barski
authors.affiliation: Division of Reproductive Sciences, Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA. satoshi.namekawa@cchmc.org.|Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 49229, USA. satoshi.namekawa@cchmc.org.
authors.forename: Satoshi H
authors.initials: SH
authors.lastname: Namekawa
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002843:Chromatin / Q000737:chemistry / Q000235:genetics*; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental; D050172:Genes, X-Linked; D005854:Germ Cells / Q000166:cytology* / Q000378:metabolism; D006657:Histones / Q000737:chemistry / Q000235:genetics; D008297:Male; D008540:Meiosis; D008810:Mice, Inbred C57BL; D008938:Mitosis; D012730:Sex Chromosomes / Q000737:chemistry / Q000235:genetics*; D013091:Spermatogenesis; D015533:Transcriptional Activation; D059467:Transcriptome; D049951:X Chromosome Inactivation
chemical_list: D002843:Chromatin; D006657:Histones