Mouse BAZ1A (ACF1) is dispensable for double-strand break repair but is essential for averting improper gene expression during spermatogenesis Journal Article


Authors: Dowdle, J. A.; Mehta, M.; Kass, E. M.; Vuong, B. Q.; Inagaki, A.; Egli, D.; Jasin, M.; Keeney, S.
Article Title: Mouse BAZ1A (ACF1) is dispensable for double-strand break repair but is essential for averting improper gene expression during spermatogenesis
Abstract: ATP-dependent chromatin remodelers control DNA access for transcription, recombination, and other processes. Acf1 (also known as BAZ1A in mammals) is a defining subunit of the conserved ISWI-family chromatin remodelers ACF and CHRAC, first purified over 15 years ago from Drosophila melanogaster embryos. Much is known about biochemical properties of ACF and CHRAC, which move nucleosomes in vitro and in vivo to establish ordered chromatin arrays. Genetic studies in yeast, flies and cultured human cells clearly implicate these complexes in transcriptional repression via control of chromatin structures. RNAi experiments in transformed mammalian cells in culture also implicate ACF and CHRAC in DNA damage checkpoints and double-strand break repair. However, their essential in vivo roles in mammals are unknown. Here, we show that Baz1a-knockout mice are viable and able to repair developmentally programmed DNA double-strand breaks in the immune system and germ line, I-SceI endonuclease-induced breaks in primary fibroblasts via homologous recombination, and DNA damage from mitomycin C exposure in vivo. However, Baz1a deficiency causes male-specific sterility in accord with its high expression in male germ cells, where it displays dynamic, stage-specific patterns of chromosomal localization. Sterility is caused by pronounced defects in sperm development, most likely a consequence of massively perturbed gene expression in spermatocytes and round spermatids in the absence of BAZ1A: the normal spermiogenic transcription program is largely intact but more than 900 other genes are mis-regulated, primarily reflecting inappropriate up-regulation. We propose that large-scale changes in chromatin composition that occur during spermatogenesis create a window of vulnerability to promiscuous transcription changes, with an essential function of ACF and/or CHRAC chromatin remodeling activities being to safeguard against these alterations. © 2013 Dowdle et al.
Journal Title: PLoS Genetics
Volume: 9
Issue: 11
ISSN: 1553-7390
Publisher: Public Library of Science  
Date Published: 2013-11-07
Start Page: e1003945
Language: English
DOI: 10.1371/journal.pgen.1003945
PROVIDER: scopus
PMCID: PMC3820798
PUBMED: 24244200
DOI/URL:
Notes: Export Date: 2 January 2014 -- Source: Scopus
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MSK Authors
  1. Scott N Keeney
    138 Keeney
  2. Maria Jasin
    250 Jasin
  3. Bao Q Vuong
    9 Vuong
  4. Elizabeth M Kass
    13 Kass
  5. Monika Mehta
    1 Mehta
  6. James Dowdle
    2 Dowdle