Homology-directed repair is a major double-strand break repair pathway in mammalian cells Journal Article


Authors: Liang, F.; Han, M.; Romanienko, P. J.; Jasin, M.
Article Title: Homology-directed repair is a major double-strand break repair pathway in mammalian cells
Abstract: Mammalian cells have been presumed to repair potentially lethal chromosomal double-strand breaks (DSBs) in large part by processes that do not require homology to the break site. This contrasts with Saccharomyces cerevisiae where the major DSB repair pathway is homologous recombination. Recently, it has been determined that DSBs in genomic DNA in mammalian cells can stimulate homologous recombination as much as 3 or 4 orders of magnitude, suggesting that homology-directed repair may play an important role in the repair of chromosomal breaks. To determine whether mammalian cells use recombinational repair at a significant level, we have analyzed the spectrum of repair events at a defined chromosomal break by using direct physical analysis of repair products. When an endonuclease-generated DSB is introduced into one of two direct repeats, homologous repair is found to account for 30- 50% of observed repair events. Both noncrossover and deletional homologous repair products are detected, at approximately a 1:3 ratio. These results demonstrate the importance of homologous recombination in the repair of DSBs in mammalian cells. In the remaining observed repair events, DSBs are repaired by nonhomologous processes. The nonhomologous repair events generally result in small deletions or insertions at the break site, although a small fraction of events result in larger chromosomal rearrangements. Interestingly, in two insertions, GT repeats were integrated at one of the broken chromosome ends, suggesting that DSB repair can contribute to the spread of microsatellite sequences in mammalian genomes.
Keywords: sequence deletion; nonhuman; animal cell; mammalia; animals; dna damage; homologous recombination; cells, cultured; dna repair; microsatellite dna; animalia; gene conversion; double stranded dna; genetic recombination; saccharomyces cerevisiae; recombination, genetic; chromosome breakage; chromosome rearrangement; sequence homology, nucleic acid; microsatellite repeats; cho cell; cho cells; cricetinae; single-strand annealing; restriction mapping; priority journal; article; dna end-joining; i- scei
Journal Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 95
Issue: 9
ISSN: 0027-8424
Publisher: National Academy of Sciences  
Date Published: 1998-04-28
Start Page: 5172
End Page: 5177
Language: English
DOI: 10.1073/pnas.95.9.5172
PUBMED: 9560248
PROVIDER: scopus
PMCID: PMC20233
DOI/URL:
Notes: Article -- Export Date: 12 December 2016 -- Source: Scopus
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  1. Maria Jasin
    251 Jasin
  2. Mingguang Han
    5 Han