title: Sex-specific promoters regulate Dnmt3L expression in mouse germ cells.
abstract: BACKGROUND
  Dnmt3L, a member of the DNA methyltransferase 3 family, lacks enzymatic activity but is required for de-novo methylation of imprinted genes in oocytes and for transposon repression in male germ cells.
  
  
  METHODS
  We used northern blots, RT-PCR, 5' rapid amplification of complementary DNA (cDNA) ends (RACE), RNase H mapping, real-time/quantitative RT-PCR and in situ hybridization to identify and characterize Dnmt3L transcripts produced during germ cell development.
  
  
  RESULTS
  Mouse Dnmt3L uses three sex-specific promoters, not the single promoter previously thought. A promoter active in prospermatogonia drives transcription of an mRNA encoding the full-length protein in perinatal testis, where de-novo methylation occurs. Late pachytene spermatocytes activate a second promoter in intron 9 of the Dnmt3L gene. After this stage, the predominant transcripts are three truncated mRNAs, which appear to be non-coding. We could also detect similar adult testis transcripts in humans. In the mouse ovary, an oocyte-specific promoter located in an intron of the neighbouring autoimmune regulator (Aire) gene produces a transcript with the full open reading frame (ORF). This is the only Dnmt3L transcript found in growing oocytes and is absent in the oocytes of Dnmt3L-/- females.
  
  
  CONCLUSIONS
  Sex-specific promoters control Dnmt3L expression in the mouse germ line, mirroring the situation at the Dnmt1 and Dnmt3A loci.
authors.affiliation: Stem Cells and Epigenetics Research Group, Centre for Molecular Biosciences, School of Biomedical Sciences, University of Ulster, Coleraine, UK.
authors.forename: T C
authors.initials: TC
authors.lastname: Shovlin
authors.forename: D
authors.initials: D
authors.lastname: Bourc'his
authors.forename: S
authors.initials: S
authors.lastname: La Salle
authors.forename: A
authors.initials: A
authors.lastname: O'Doherty
authors.forename: J M
authors.initials: JM
authors.lastname: Trasler
authors.forename: T H
authors.initials: TH
authors.lastname: Bestor
authors.forename: C P
authors.initials: CP
authors.lastname: Walsh
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000096:biosynthesis*; D005260:Female; D018392:Genomic Imprinting; D005854:Germ Cells / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D021141:Nucleic Acid Amplification Techniques; D009865:Oocytes / Q000201:enzymology; D010053:Ovary / Q000201:enzymology; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016914:Ribonuclease H / Q000378:metabolism; D012737:Sex Factors; D013087:Spermatids / Q000201:enzymology; D013093:Spermatogonia / Q000201:enzymology
chemical_list: C498796:Dnmt3l protein, mouse; D004248:DNA (Cytosine-5-)-Methyltransferases; D016914:Ribonuclease H