title: Epigenetics of the male gamete.
abstract: OBJECTIVE
  To review and summarize the current understanding of the epigenetic status of human sperm in regards to protamination, specific localization and modifications of retained histones, and DNA methylation.
  
  
  METHODS
  Review of the relevant literature.
  
  
  METHODS
  University-based clinical and research laboratories.
  
  
  METHODS
  Fertile and infertile men.
  
  
  METHODS
  None.
  
  
  METHODS
  Critical review of the literature.
  
  
  RESULTS
  Sperm from normospermic, fertile men have epigenetic modifications consistent with gene "poising" at the promoters of genes involved in development, including the localization of retained histones with bivalent histone modifications and hypomethylation of DNA. These epigenetic marks are altered in some patients with abnormal spermatogenesis, and in some men who exhibit unexplained, altered embryogenesis during IVF therapy.
  
  
  CONCLUSIONS
  The sperm epigenome implies a poising of the paternal genome for embryogenesis and a possible role in the establishment of totipotency of the embryo and may help in understanding some causes of reduced fertility and transmission of disease risk.
authors.affiliation: Departments of Surgery (Urology), University of Utah School of Medicine, Salt Lake City, Utah 84108, USA. douglas.carrell@hsc.utah.edu
authors.forename: Douglas T
authors.initials: DT
authors.lastname: Carrell
mesh_terms: D042002:Chromatin Assembly and Disassembly; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005298:Fertility / Q000235:genetics*; D006657:Histones / Q000378:metabolism; D006801:Humans; D007248:Infertility, Male / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D011479:Protamines / Q000378:metabolism; D013091:Spermatogenesis / Q000235:genetics*; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D006657:Histones; D011479:Protamines