title: Effect of oocyte vitrification on deoxyribonucleic acid methylation of H19, Peg3, and Snrpn differentially methylated regions in mouse blastocysts.
abstract: OBJECTIVE
  To examine whether mouse oocytes vitrification could alter the deoxyribonucleic acid (DNA) methylation of differentially methylated regions (DMRs) of three imprinted genes in in vitro fertilized blastocysts.
  
  
  METHODS
  In vitro experiments using murine model.
  
  
  METHODS
  State key laboratory and university research laboratory.
  
  
  METHODS
  Kunming white mice.
  
  
  METHODS
  The mouse metaphase II oocytes were vitrified. After thawing, the surviving oocytes were fertilized in vitro to produce blastocysts. The blastocysts derived in vitro from fresh oocytes were used as a control. The DNA methylation patterns of the DMRs of imprinted genes in oocytes and blastocysts and the relative expression of DNMTs (Dnmt1, Dnmt3a, Dnmt3b, and Dnmt3l) in oocytes and blastocysts were detected.
  
  
  METHODS
  Methylation patterns of DMRs of H19, Peg3, and Snrpn analyzed by bisulfite mutagenesis and sequencing. Expression levels of messenger ribonucleic acid as measured by real-time reverse-transcriptase polymerase chain reaction.
  
  
  RESULTS
  After oocytes vitrification, the methylation levels at H19, Peg3, and Snrpn DMRs in blastocysts were decreased. However, there was no significant difference in the percentage of hypermethylated strands at Peg3 DMRs between the vitrified and control groups. DNMTs expression in vitrified oocytes and the expression of Dnmt3b in blastocysts derived from vitrified oocytes were significantly reduced.
  
  
  CONCLUSIONS
  Oocytes vitrification could lead to the loss of DNA methylation of imprinted genes (H19, Peg3, and Snrpn) in mouse blastocysts, which is mainly caused by the reductions of DNMTs after vitrification of oocytes.
authors: Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China.
authors: Ke-Ren
authors: KR
authors: Cheng
authors: Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China.
authors: Xiang-Wei
authors: XW
authors: Fu
authors: Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China.
authors: Rui-Na
authors: RN
authors: Zhang
authors: Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China.
authors: Gong-Xue
authors: GX
authors: Jia
authors: State Key Laboratory for Agro Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China.
authors: Yun-Peng
authors: YP
authors: Hou
authors: Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China. Electronic address: zhushien@cau.edu.cn.
authors: Shi-En
authors: SE
authors: Zhu
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D015925:Cryopreservation; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics; D005260:Female; D005307:Fertilization in Vitro; D018507:Gene Expression Regulation, Developmental; D018392:Genomic Imprinting; D051741:Kruppel-Like Transcription Factors / Q000235:genetics*; D051379:Mice; D009865:Oocytes; D062085:RNA, Long Noncoding / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D014021:Tissue Preservation / Q000379:methods*; D058989:Vitrification; D055517:snRNP Core Proteins / Q000235:genetics*
chemical_list: C094335:H19 long non-coding RNA; D051741:Kruppel-Like Transcription Factors; C097901:Peg3 protein, mouse; D062085:RNA, Long Noncoding; D012333:RNA, Messenger; D055517:snRNP Core Proteins; D015254:DNA Modification Methylases
keywords: DNA methylation; DNMTs; Vitrification; blastocyst; mouse oocyte