title: Stage-specific roles for tet1 and tet2 in DNA demethylation in primordial germ cells.
abstract: Primordial germ cells (PGCs) undergo dramatic rearrangements to their methylome during embryogenesis, including initial genome-wide DNA demethylation that establishes the germline epigenetic ground state. The role of the 5-methylcytosine (5mC) dioxygenases Tet1 and Tet2 in the initial genome-wide DNA demethylation process has not been examined directly. Using PGCs differentiated from either control or Tet2(-/-); Tet1 knockdown embryonic stem cells (ESCs), we show that in vitro PGC (iPGC) formation and genome-wide DNA demethylation are unaffected by the absence of Tet1 and Tet2, and thus 5-hydroxymethylcytosine (5hmC). However, numerous promoters and gene bodies were hypermethylated in mutant iPGCs, which is consistent with a role for 5hmC as an intermediate in locus-specific demethylation. Altogether, our results support a revised model of PGC DNA demethylation in which the first phase of comprehensive 5mC loss does not involve 5hmC. Instead, Tet1 and Tet2 have a locus-specific role in shaping the PGC epigenome during subsequent development.
authors: Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
authors: John J
authors: JJ
authors: Vincent
authors: Yun
authors: Y
authors: Huang
authors: Pao-Yang
authors: PY
authors: Chen
authors: Suhua
authors: S
authors: Feng
authors: Joseph H
authors: JH
authors: Calvopiña
authors: Kevin
authors: K
authors: Nee
authors: Serena A
authors: SA
authors: Lee
authors: Thuc
authors: T
authors: Le
authors: Alexander J
authors: AJ
authors: Yoon
authors: Kym
authors: K
authors: Faull
authors: Guoping
authors: G
authors: Fan
authors: Anjana
authors: A
authors: Rao
authors: Steven E
authors: SE
authors: Jacobsen
authors: Matteo
authors: M
authors: Pellegrini
authors: Amander T
authors: AT
authors: Clark
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives; D000818:Animals; D002454:Cell Differentiation; D003596:Cytosine / Q000031:analogs & derivatives / Q000378:metabolism; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000378:metabolism*; D049308:Dioxygenases; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D016678:Genome / Q000235:genetics; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D051379:Mice; D011518:Proto-Oncogene Proteins / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C540839:TET1 protein, mouse; C011865:5-hydroxymethylcytosine; D049452:Green Fluorescent Proteins; D044503:5-Methylcytosine; D003596:Cytosine; D049308:Dioxygenases; C551914:Tet2 protein, mouse