title: Chd1 is essential for the high transcriptional output and rapid growth of the mouse epiblast.
abstract: The pluripotent mammalian epiblast undergoes unusually fast cell proliferation. This rapid growth is expected to generate a high transcriptional demand, but the underlying mechanisms remain unknown. We show here that the chromatin remodeler Chd1 is required for transcriptional output and development of the mouse epiblast. Chd1(-/-) embryos exhibit proliferation defects and increased apoptosis, are smaller than controls by E5.5 and fail to grow, to become patterned or to gastrulate. Removal of p53 allows progression of Chd1(-/-) mutants only to E7.0-8.0, highlighting the crucial requirement for Chd1 during early post-implantation development. Chd1(-/-) embryonic stem cells (ESCs) have a self-renewal defect and a genome-wide reduction in transcriptional output at both known mRNAs and intergenic transcripts. These transcriptional defects were only uncovered when cell number-normalized approaches were used, and correlate with a lower engagement of RNAP II with transcribed genes in Chd1(-/-) ESCs. We further show that Chd1 directly binds to ribosomal DNA, and that both Chd1(-/-) epiblast cells in vivo and ESCs in vitro express significantly lower levels of ribosomal RNA. In agreement with these findings, mutant cells in vivo and in vitro exhibit smaller and more elongated nucleoli. Thus, the RNA output by both Pol I and II is reduced in Chd1(-/-) cells. Our data indicate that Chd1 promotes a globally elevated transcriptional output required to sustain the distinctly rapid growth of the mouse epiblast.
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Marcela
authors.initials: M
authors.lastname: Guzman-Ayala
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Sachs
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Fong Ming
authors.initials: FM
authors.lastname: Koh
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Institute for Human Genetics, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Department of Epidemiology and Biostatistics, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Courtney
authors.initials: C
authors.lastname: Onodera
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Aydan
authors.initials: A
authors.lastname: Bulut-Karslioglu
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Chih-Jen
authors.initials: CJ
authors.lastname: Lin
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Priscilla
authors.initials: P
authors.lastname: Wong
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Nitta
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Institute for Human Genetics, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Department of Epidemiology and Biostatistics, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA.
authors.forename: Jun S
authors.initials: JS
authors.lastname: Song
authors.affiliation: Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, 35 Medical Center Way, University of California, San Francisco, CA 94143, USA miguel.ramalho-santos@ucsf.edu.
authors.forename: Miguel
authors.initials: M
authors.lastname: Ramalho-Santos
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D019521:Body Patterning / Q000235:genetics; D002453:Cell Cycle / Q000235:genetics; D003433:Crosses, Genetic; D004275:DNA, Ribosomal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D047108:Embryonic Development; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D054262:Gastrulation / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D005855:Germ Layers / Q000254:growth & development* / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D012322:RNA Precursors / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: C489844:Chd1 protein, mouse; D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; D012322:RNA Precursors
keywords: Chromatin; Epiblast proliferation; Epigenetics; Pluripotency; Transcription