Rad51-deficient vertebrate cells accumulate chromosomal breaks prior to cell death.
Yeast rad51 mutants are viable, but extremely sensitive to gamma-rays due to defective repair of double-strand breaks. In contrast, disruption of the murine RAD51 homologue is lethal, indicating an essential role of Rad51 in vertebrate cells. We generated clones of the chicken B lymphocyte line DT40 carrying a human RAD51 transgene under the control of a repressible promoter and subsequently disrupted the endogenous RAD51 loci. Upon inhibition of the RAD51 transgene, Rad51- cells accumulated in the G2/M phase of the cell cycle before dying. Chromosome analysis revealed that most metaphase-arrested Rad51- cells carried isochromatid-type breaks. In conclusion, Rad51 fulfils an essential role in the repair of spontaneously occurring chromosome breaks in proliferating cells of higher eukaryotes.
Sonoda
E
E
Bayer Chair, Department of Molecular Immunology and Allergology, Faculty of Medicine, Kyoto University, Japan.
Sasaki
M S
MS
Buerstedde
J M
JM
Bezzubova
O
O
Shinohara
A
A
Ogawa
H
H
Takata
M
M
Yamaguchi-Iwai
Y
Y
Takeda
S
S
D000818:Animals; D030161:Avian Proteins; D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology*; D016923:Cell Death / Q000235:genetics; D002460:Cell Line; D002645:Chickens; D002869:Chromosome Aberrations / Q000235:genetics*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D016195:G2 Phase / Q000235:genetics; D017353:Gene Deletion; D015870:Gene Expression; D018390:Gene Targeting; D008938:Mitosis / Q000235:genetics; D051135:Rad51 Recombinase; D014162:Transfection
D030161:Avian Proteins; D004268:DNA-Binding Proteins; C495150:RAD51 protein, Gallus gallus; D051135:Rad51 Recombinase