title: Laser microbeam-induced DNA damage inhibits cell division in fertilized eggs and early embryos.
abstract: DNA double-strand breaks are caused by both intracellular physiological processes and environmental stress. In this study, we used laser microbeam cut (abbreviated microcut or cut), which allows specific DNA damage in the pronucleus of a fertilized egg and in individual blastomere(s) of an early embryo, to investigate the response of early embryos to DNA double-strand breaks. Line type γH2AX foci were detected in the cut region, while Chk2 phosphorylation staining was observed in the whole nuclear region of the cut pronuclei or blastomeres. Zygotes with cut male or female pronucleus showed poor developmental capability: the percentage of cleavage embryos was significantly decreased, and the embryos failed to complete further development to blastocysts. The cut blastomeres in 2-cell, 4-cell, and 8-cell embryos ceased cleavage, and they failed to incorporate into compacted morulae, but instead underwent apoptosis and cell death at the blastocyst stage; the uncut part of embryos could develop to blastocysts, with a reduced percentage or decreased cell number. When both blastomeres of the 2-cell embryos were cut by laser microbeam, cell death occurred 24 h earlier, suggesting important functions of the uncut blastomere in delaying cell death of the cut blastomere. Taken together, we conclude that microbeam-induced DNA damage in early embryos causes compromised development, and that embryos may have their own mechanisms to exclude DNA-damaged blastomeres from participating in further development.
authors.affiliation: State Key Laboratory of Reproductive Biology; Institute of Zoology; Chinese Academy of Sciences; Beijing, China.
authors.forename: Zhong-Wei
authors.initials: ZW
authors.lastname: Wang
authors.forename: Xue-Shan
authors.initials: XS
authors.lastname: Ma
authors.forename: Jun-Yu
authors.initials: JY
authors.lastname: Ma
authors.forename: Yi-Bo
authors.initials: YB
authors.lastname: Luo
authors.forename: Fei
authors.initials: F
authors.lastname: Lin
authors.forename: Zhen-Bo
authors.initials: ZB
authors.lastname: Wang
authors.forename: Heng-Yu
authors.initials: HY
authors.lastname: Fan
authors.forename: Heide
authors.initials: H
authors.lastname: Schatten
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Sun
mesh_terms: D000818:Animals; D001757:Blastomeres / Q000166:cytology; D000071616:CDX2 Transcription Factor; D002455:Cell Division; D019070:Cell Lineage; D004249:DNA Damage; D004622:Embryo, Mammalian / Q000166:cytology*; D047108:Embryonic Development; D005260:Female; D005306:Fertilization / Q000502:physiology*; D018398:Homeodomain Proteins / Q000378:metabolism; D007834:Lasers; D008297:Male; D008813:Mice, Inbred ICR; D009028:Morula / Q000166:cytology; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D009865:Oocytes / Q000166:cytology; D010063:Ovum / Q000166:cytology*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D000071616:CDX2 Transcription Factor; C487514:Cdx2 protein, mouse; D018398:Homeodomain Proteins; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D014157:Transcription Factors
keywords: DNA damage; blastomeres; embryos; laser micro beam; zygotes
references.citation: J Reprod Dev. 2005 Apr;51(2):281-7
references.pmid: 15699582
references.citation: Biol Reprod. 2009 Apr;80(4):813-22
references.pmid: 19109225
references.citation: Fertil Steril. 2011 Jul;96(1):187-92
references.pmid: 21550043
references.citation: PLoS One. 2012;7(8):e43875
references.pmid: 22928046
references.citation: Nature. 1959 Oct 24;184:1286-7
references.pmid: 13836947
references.citation: In Vivo. 2012 Sep-Oct;26(5):827-34
references.pmid: 22949597
references.citation: Genes Dev. 1998 Jun 1;12(11):1551-70
references.pmid: 9620844
references.citation: Electromagn Biol Med. 2011 Dec;30(4):246-52
references.pmid: 22047462
references.citation: Biol Reprod. 2006 Nov;75(5):673-80
references.pmid: 16855210
references.citation: Prog Nucleic Acid Res Mol Biol. 1988;35:95-125
references.pmid: 3065826
references.citation: Biochem Biophys Res Commun. 2007 Jun 29;358(2):578-84
references.pmid: 17498656
references.citation: J Cell Biol. 1999 Sep 6;146(5):905-16
references.pmid: 10477747
references.citation: PLoS One. 2012;7(6):e38742
references.pmid: 22745678
references.citation: Autophagy. 2012 Dec;8(12):1822-23
references.pmid: 22929123
references.citation: J Androl. 2006 Mar-Apr;27(2):176-88
references.pmid: 16304212
references.citation: J Radiat Res. 2009 Jan;50(1):11-7
references.pmid: 19218778
references.citation: Curr Biol. 2000 Jul 27-Aug 10;10(15):886-95
references.pmid: 10959836
references.citation: Mol Cell. 2012 Apr 27;46(2):212-25
references.pmid: 22424773
references.citation: Front Genet. 2013 Jun 24;4:117
references.pmid: 23805152
references.citation: Toxicol Sci. 2007 Dec;100(2):495-503
references.pmid: 17872895
references.citation: J Biol Regul Homeost Agents. 2004 Apr-Jun;18(2):106-14
references.pmid: 15471212
references.citation: Biol Reprod. 2011 Sep;85(3):524-35
references.pmid: 21593482
references.citation: Nucleic Acids Res. 2009 May;37(9):e68
references.pmid: 19357094
references.citation: Biol Reprod. 2003 Aug;69(2):501-7
references.pmid: 12700186
references.citation: Mol Reprod Dev. 2002 Jan;61(1):67-77
references.pmid: 11774377
references.citation: Chem Biol Interact. 2006 Mar 10;160(1):1-40
references.pmid: 16430879
references.citation: Nat Cell Biol. 2006 Jan;8(1):37-45
references.pmid: 16327781
references.citation: Cell Cycle. 2013 Apr 15;12(8):1233-41
references.pmid: 23518501
references.citation: PLoS One. 2013;8(2):e56385
references.pmid: 23431372
references.citation: Fertil Steril. 2013 Jul;100(1):75-80
references.pmid: 23562046
references.citation: J Embryol Exp Morphol. 1981 Oct;65:165-72
references.pmid: 6895911
references.citation: Curr Biol. 2012 Jun 5;22(11):989-94
references.pmid: 22578416
references.citation: DNA Repair (Amst). 2006 Aug 13;5(8):959-71
references.pmid: 16837249
references.citation: Mutat Res. 1993 May;299(3-4):313-5
references.pmid: 7683099
references.citation: J Cell Biol. 2006 Apr 24;173(2):195-206
references.pmid: 16618811
references.citation: J Cell Biol. 1996 Jun;133(5):1053-9
references.pmid: 8655578
references.citation: Nat Cell Biol. 2003 Mar;5(3):255-60
references.pmid: 12598907
references.citation: J Reprod Fertil. 1968 Dec;17(3):527-31
references.pmid: 5715682
references.citation: Nature. 2001 Apr 12;410(6830):842-7
references.pmid: 11298456
references.citation: Proc Natl Acad Sci U S A. 2000 Sep 12;97(19):10389-94
references.pmid: 10973490
references.citation: Nat Struct Mol Biol. 2012 May 06;19(6):628-32
references.pmid: 22562137
references.citation: Hum Reprod. 2008 Aug;23(8):1742-7
references.pmid: 18503052