title: Evidence for conserved DNA and histone H3 methylation reprogramming in mouse, bovine and rabbit zygotes.
abstract: BACKGROUND
  In mammals the parental genomes are epigenetically reprogrammed after fertilization. This reprogramming includes a rapid demethylation of the paternal (sperm-derived) chromosomes prior to DNA replication in zygotes. Such active DNA demethylation in the zygote has been documented for several mammalian species, including mouse, rat, pig, human and cow, but questioned to occur in rabbit.
  
  
  RESULTS
  When comparing immunohistochemical patterns of antibodies against 5-methyl-cytosine, H3K4me3 and H3K9me2 modifications we observe similar pronuclear distribution and dynamics in mouse, bovine and rabbit zygotes. In rabbit DNA demethylation of the paternal chromosomes occurs at slightly advanced pronuclear stages. We also show that the rabbit oocyte rapidly demethylates DNA of donor fibroblast after nuclear transfer.
  
  
  CONCLUSIONS
  Our data reveal that major events of epigenetic reprogramming during pronuclear maturation, including mechanisms of active DNA demethylation, are apparently conserved among mammalian species.
authors.affiliation: University of Saarland, Natural Sciences - Technical Faculty III, Biological Sciences, Genetics/Epigenetics, 66123 Saarbrücken, Germany. k.lepikhov@mx.uni-saarland.de
authors.forename: Konstantin
authors.initials: K
authors.lastname: Lepikhov
authors.forename: Valeri
authors.initials: V
authors.lastname: Zakhartchenko
authors.forename: Ru
authors.initials: R
authors.lastname: Hao
authors.forename: Feikun
authors.initials: F
authors.lastname: Yang
authors.forename: Christine
authors.initials: C
authors.lastname: Wrenzycki
authors.forename: Heiner
authors.initials: H
authors.lastname: Niemann
authors.forename: Eckhard
authors.initials: E
authors.lastname: Wolf
authors.forename: Joern
authors.initials: J
authors.lastname: Walter