Knockdown of zebrafish Fancd2 causes developmental abnormalities via p53-dependent apoptosis.
Mechanisms underlying the multiple developmental defects observed in Fanconi anemia (FA) patients are not well defined. We have identified the zebrafish homolog of human FANCD2, which encodes a nuclear effector protein that is monoubiquitinated in response to DNA damage, targeting it to nuclear foci where it preserves chromosomal integrity. Fancd2-deficient zebrafish embryos develop defects similar to those found in children with FA, including shortened body length, microcephaly, and microophthalmia, which are due to extensive cellular apoptosis. Developmental defects and increased apoptosis in Fancd2-deficient zebrafish were corrected by injection of human FANCD2 or zebrafish bcl2 mRNA, or by knockdown of p53, indicating that in the absence of Fancd2, developing tissues spontaneously undergo p53-dependent apoptosis. Thus, Fancd2 is essential during embryogenesis to prevent inappropriate apoptosis in neural cells and other tissues undergoing high levels of proliferative expansion, implicating this mechanism in the congenital abnormalities observed in human infants with FA.
Liu
Ting Xi
TX
Department of Pediatric Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115, USA.
Howlett
Niall G
NG
Deng
Min
M
Langenau
David M
DM
Hsu
Karl
K
Rhodes
Jennifer
J
Kanki
John P
JP
D'Andrea
Alan D
AD
Look
A Thomas
AT
D000015:Abnormalities, Multiple / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004852:Epoxy Compounds / Q000494:pharmacology; D005199:Fanconi Anemia / Q000235:genetics*; D052236:Fanconi Anemia Complementation Group D2 Protein; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D012333:RNA, Messenger / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics; D015027:Zebrafish
D003432:Cross-Linking Reagents; D004852:Epoxy Compounds; C499905:FANCD2 protein, human; D052236:Fanconi Anemia Complementation Group D2 Protein; D009687:Nuclear Proteins; D016376:Oligonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; C007366:diepoxybutane