Especially for point mutations, expanded simple tandem repeats and structural chromosome mutations, the contribution of the male germline is dominant.
Hum Mol Genet. 2008 Jul 1;17(13):1922-37. Epub 2008 Mar 18.
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DNA double-strand break repair in parental chromatin of mouse zygotes, the first cell cycle as an origin of de novo mutation.
Derijck A, van der Heijden G, Giele M, Philippens M, de Boer P.
Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
In the human, the contribution of the sexes to the genetic load is dissimilar. Especially for point mutations, expanded simple tandem repeats and structural chromosome mutations, the contribution of the male germline is dominant. Far less is known about the male germ cell stage(s) that are most vulnerable to mutation contraction. For the understanding of de novo mutation induction in the germline, mechanistic insight of DNA repair in the zygote is mandatory. At the onset of embryonic development, the parental chromatin sets occupy one pronucleus (PN) each and DNA repair can be regarded as a maternal trait, depending on proteins and mRNAs provided by the oocyte. Repair of DNA double-strand breaks (DSBs) is executed by non-homologous end joining (NHEJ) and homologous recombination (HR). Differentiated somatic cells often resolve DSBs by NHEJ, whereas embryonic stem cells preferably use HR. We show NHEJ and HR to be both functional during the zygotic cell cycle. NHEJ is already active during replacement of sperm protamines by nucleosomes. The kinetics of G1 repair is influenced by DNA-PK(cs) hypomorphic activity. Both HR and NHEJ are operative in S-phase, HR being more active in the male PN. DNA-PK(cs) deficiency upregulates the HR activity. Both after sperm remodeling and at first mitosis, spontaneous levels of gammaH2AX foci (marker for DSBs) are high. All immunoflurescent indices of DNA damage and DNA repair point at greater spontaneous damage and induced repair activity in paternal chromatin in the zygote.
PMID: 18353795 [PubMed - indexed for MEDLINE]
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gammaH2AX signalling during sperm chromatin remodelling in the mouse zygote. [DNA Repair (Amst). 2006]
Mechanisms of DNA double strand break repair and chromosome aberration formation. [Cytogenet Genome Res. 2004]
An xrcc4 defect or Wortmannin stimulates homologous recombination specifically induced by double-strand breaks in mammalian cells. [Nucleic Acids Res. 2002]
Differential H4 acetylation of paternal and maternal chromatin precedes DNA replication and differential transcriptional activity in pronuclei of 1-cell mouse embryos. [Development. 1997]
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Links
DNA double-strand break repair in parental chromatin of mouse zygotes, the first cell cycle as an origin of de novo mutation.
Derijck A, van der Heijden G, Giele M, Philippens M, de Boer P.
Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
In the human, the contribution of the sexes to the genetic load is dissimilar. Especially for point mutations, expanded simple tandem repeats and structural chromosome mutations, the contribution of the male germline is dominant. Far less is known about the male germ cell stage(s) that are most vulnerable to mutation contraction. For the understanding of de novo mutation induction in the germline, mechanistic insight of DNA repair in the zygote is mandatory. At the onset of embryonic development, the parental chromatin sets occupy one pronucleus (PN) each and DNA repair can be regarded as a maternal trait, depending on proteins and mRNAs provided by the oocyte. Repair of DNA double-strand breaks (DSBs) is executed by non-homologous end joining (NHEJ) and homologous recombination (HR). Differentiated somatic cells often resolve DSBs by NHEJ, whereas embryonic stem cells preferably use HR. We show NHEJ and HR to be both functional during the zygotic cell cycle. NHEJ is already active during replacement of sperm protamines by nucleosomes. The kinetics of G1 repair is influenced by DNA-PK(cs) hypomorphic activity. Both HR and NHEJ are operative in S-phase, HR being more active in the male PN. DNA-PK(cs) deficiency upregulates the HR activity. Both after sperm remodeling and at first mitosis, spontaneous levels of gammaH2AX foci (marker for DSBs) are high. All immunoflurescent indices of DNA damage and DNA repair point at greater spontaneous damage and induced repair activity in paternal chromatin in the zygote.
PMID: 18353795 [PubMed - indexed for MEDLINE]
Related Articles
gammaH2AX signalling during sperm chromatin remodelling in the mouse zygote. [DNA Repair (Amst). 2006]
Mechanisms of DNA double strand break repair and chromosome aberration formation. [Cytogenet Genome Res. 2004]
An xrcc4 defect or Wortmannin stimulates homologous recombination specifically induced by double-strand breaks in mammalian cells. [Nucleic Acids Res. 2002]
Differential H4 acetylation of paternal and maternal chromatin precedes DNA replication and differential transcriptional activity in pronuclei of 1-cell mouse embryos. [Development. 1997]
Ionizing radiation and genetic risks XIV. Potential research directions in the post-genome era based on knowledge of repair of radiation-induced DNA double-strand breaks in mammalian somatic cells and the origin of deletions associated with human genomic disorders. [Mutat Res. 2005]
Labels: Especially for point mutations, expanded simple tandem repeats and structural chromosome mutations, the contribution of the male germline is dominant.
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