title: Dynamic changes of histone H3 trimethylated at positions K4 and K27 in human oocytes and preimplantation embryos.
abstract: OBJECTIVE
  To investigate the distribution patterns of H3K4me3 and H3K27me3 in human oocytes and preimplantation embryos.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  University reproductive medical center.
  
  
  METHODS
  Patients undergoing IVF cycles.
  
  
  METHODS
  Oocytes and embryos were collected from patients undergoing IVF cycles.
  
  
  METHODS
  The distribution patterns of H3K4me3 and H3K27me3 in oocytes and embryos were analyzed by indirect immunofluorescent staining and scanning confocal microscopy.
  
  
  RESULTS
  H3K4me3 and H3K27me3 signals were detectable at each stage of oocyte and embryonic development. However, only one of the pronuclei showed signal for H3K27me3 in each of the zygotes, whereas H3K4me3 staining was always uniform in all zygotes. The level of H3K4me3 decreased steadily from germinal vesicle to metaphase II stage, obviously increased from zygote stage to four-cell stage, and reached the lowest at eight-cell stage. A sharp increase was then observed at blastocyst stage. The level of H3K27me3 slightly changed from germinal vesicle stage to zygote stage, then decreased steadily and reached the lowest at eight-cell stage, followed by a significant increase at blastocyst stage.
  
  
  CONCLUSIONS
  The levels of H3K4me3 and H3K27me3 show dynamic changes during human oocyte maturation and preimplantation embryonic development. Asymmetric distribution of H3K27me3 exists in human zygote pronuclei, whereas H3K4me3 is always uniform in all of the pronuclei.
authors: Department of Histology and Embryology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: Aijun
authors: A
authors: Zhang
authors: Bufang
authors: B
authors: Xu
authors: Yijuan
authors: Y
authors: Sun
authors: Xiaowei
authors: X
authors: Lu
authors: Ruihuan
authors: R
authors: Gu
authors: Ling
authors: L
authors: Wu
authors: Yun
authors: Y
authors: Feng
authors: Chen
authors: C
authors: Xu
mesh_terms: D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D001757:Blastomeres / Q000166:cytology / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D046149:Embryo Culture Techniques; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D019084:Fluorescent Antibody Technique, Indirect; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008745:Methylation; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D015053:Zygote / Q000166:cytology / Q000378:metabolism
chemical_list: D006657:Histones