Aging impairs double-strand break repair by homologous recombination in Drosophila germ cells

Laetitia Delabaere, Henry A. Ertl, Dashiell J. Massey, Carolyn M. Hofley, Faraz Sohail, Elisa Bienenstock, Hans Sebastian, Irene Chiolo, Jeannine R. LaRocque

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

Aging is characterized by genome instability, which contributes to cancer formation and cell lethality leading to organismal decline. The high levels of DNA double-strand breaks (DSBs) observed in old cells and premature aging syndromes are likely a primary source of genome instability, but the underlying cause of their formation is still unclear. DSBs might result from higher levels of damage or repair defects emerging with advancing age, but repair pathways in old organisms are still poorly understood. Here, we show that premeiotic germline cells of young and old flies have distinct differences in their ability to repair DSBs by the error-free pathway homologous recombination (HR). Repair of DSBs induced by either ionizing radiation (IR) or the endonuclease I-SceI is markedly defective in older flies. This correlates with a remarkable reduction in HR repair measured with the DR-white DSB repair reporter assay. Strikingly, most of this repair defect is already present at 8 days of age. Finally, HR defects correlate with increased expression of early HR components and increased recruitment of Rad51 to damage in older organisms. Thus, we propose that the defect in the HR pathway for germ cells in older flies occurs following Rad51 recruitment. These data reveal that DSB repair defects arise early in the aging process and suggest that HR deficiencies are a leading cause of genome instability in germ cells of older animals.

Original languageEnglish (US)
Pages (from-to)320-328
Number of pages9
JournalAging Cell
Volume16
Issue number2
DOIs
StatePublished - Apr 1 2017

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Keywords

  • Drosophila melanogaster
  • Rad51
  • aging
  • double-strand break repair
  • homologous recombination

ASJC Scopus subject areas

  • Aging
  • Cell Biology

Cite this

Delabaere, L., Ertl, H. A., Massey, D. J., Hofley, C. M., Sohail, F., Bienenstock, E., Sebastian, H., Chiolo, I., & LaRocque, J. R. (2017). Aging impairs double-strand break repair by homologous recombination in Drosophila germ cells. Aging Cell, 16(2), 320-328. https://doi.org/10.1111/acel.12556