title: The impact of ovarian stimulation on the expression of candidate reprogramming genes in mouse preimplantation embryos.
abstract: Ovarian stimulation with gonadotrophins is an integral part of assisted reproductive technologies in human subfertility/infertility treatment. Recent findings have associated ovarian stimulation with the increased incidence of imprinting disorders in humans as well as defects in genome-wide methylation reprogramming and, in particular, imprinting in mice. Here, we present the first study that determined the impact of ovarian stimulation on the expression of developmentally important reprogramming genes (Apex1, Lig1, Lig3, Mbd2, Mbd3, Mbd4, and Polb) in single early mouse morula embryos (16-cell stage). Using absolute quantification of mRNA by quantitative real-time PCR, we observed an association of ovarian stimulation with a downregulation of mRNAs encoding the base excision repair proteins APEX1 and POLB as well as the 5-methyl-CpG-binding domain protein MBD3 in individual morula embryos. Whole mount immunofluorescence staining of early and late morula embryos with an antibody against APEX1 revealed individual embryos with lower protein expression levels after ovarian stimulation and a correlation of mRNA expression with protein abundance. Our data argue for a negative impact of ovarian stimulation during female gametogenesis and/or early embryo development affecting the expression of candidate reprogramming factors.
authors.affiliation: Institute of Human Genetics, Johannes Gutenberg University, Mainz, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Linke
authors.forename: A
authors.initials: A
authors.lastname: May
authors.forename: K
authors.initials: K
authors.lastname: Reifenberg
authors.forename: T
authors.initials: T
authors.lastname: Haaf
authors.forename: U
authors.initials: U
authors.lastname: Zechner
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D019951:DNA Polymerase beta / Q000235:genetics / Q000378:metabolism; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006064:Gonadotropins, Equine / Q000494:pharmacology; D006736:Horses; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D009866:Oogenesis / Q000187:drug effects / Q000235:genetics*; D010062:Ovulation Induction / Q000379:methods*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D006063:Chorionic Gonadotropin; D004268:DNA-Binding Proteins; D006064:Gonadotropins, Equine; C492013:Mbd3 protein, mouse; D012333:RNA, Messenger; D014157:Transcription Factors; D019951:DNA Polymerase beta; C486216:Apex1 protein, mouse; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase